The Learning Rabbit Hole

I. The Importance of Forgetting

Forgetting is usually framed as failure. The cognitive science suggests it is partly a feature.

The brain that retained everything would be overwhelmed. The selective forgetting that discards low-value information frees capacity for what matters. The case of Solomon Shereshevsky (the Russian mnemonist studied by Alexander Luria) illustrates the problem; his near-perfect memory made abstraction and generalisation difficult because he could not let go of specific details to see the patterns beneath them.

Worth exploring: the relationship between forgetting and creativity, the role of forgetting in updating outdated models, the distinction between retrieval failure and genuine erasure, and the implications for how much we should try to retain versus externalise (see Brain 2.0). The forgetting curve (Ebbinghaus) and spaced repetition as the engineered response to it also belong here.

II. Memory Competitions and the Method of Loci

Competitive memorisation is a developed discipline with documented techniques. The method of loci (memory palace), the major system, the person-action-object system. Memory athletes can memorise the order of multiple shuffled card decks, thousands of digits, and extensive word lists.

The territory worth exploring: these techniques work for discrete information (numbers, sequences, lists) but produce limited transfer to understanding. The reminder from Discovery Basics applies: memory techniques are valuable for genuinely important information and a waste of energy when deployed for the sake of remembering (as in competitions). The competition is impressive and mostly disconnected from learning. Moonwalking with Einstein (Joshua Foer) documents the competitive memory world from the inside.

III. Information Storage Requirements and the Connection Search

As external storage becomes near-universal, the value of the brain shifts from storage toward connection and creativity. The brain that no longer needs to store facts can be freed to search for connections between facts that are stored externally.

Worth exploring: whether the change is genuinely beneficial or whether it produces cognitive atrophy (the Brain 2.0 AI extension question), the relationship between stored knowledge and the capacity to generate insight (you can’t connect what you don’t hold), and the optimal balance between internal retention and external storage. 

IV. The Biology of Learning Deep Dive

The neuroplasticity foundations covered in Discovery Basics and the Neuroplasticity Super-Protocol in the Learning Cheatsheet draw on Huberman’s synthesis. The deeper material worth exploring:

• Neuroplasticity is not the goal; it is a capacity for change: The question is always what end the change serves. Self-directed plasticity (deliberately shaping your own brain change) is distinct from the passive plasticity of childhood.
• Until roughly age 25, learning can occur passively: As an adult, change requires deliberate attention and motivation. The framing: attention plus awareness equals change. The adult brain can change, but only with selective attention and motivation directed at the specific change.
• Competition is the route to plasticity: You cannot add new capacity without energetic competition in the brain. Learning something new involves the relative strengthening of some pathways and weakening of others. The brain doesn’t simply accumulate; it reallocates.
• The new-neuron myth: New neurons occur in the olfactory bulb and hippocampus in animal studies; human adult neurogenesis is more limited and contested than popular accounts suggest. The plasticity in adults comes from synaptic reorganisation rather than new neurons.

V. The Neuromodulator Architecture for Learning

The chemical substrate that gates adult plasticity. 

• The chemical trio: Epinephrine for alertness, acetylcholine for focused attention, dopamine for the reward signalling that consolidates the change. When all three are present during an experience, the brain is primed for change.
• Epinephrine and alertness: Released from the locus coeruleus (in the brain) and adrenal glands (in the body) during high-alertness states. Nonspecific; increases the general likelihood that neurons will be active.
• Acetylcholine and the attentional spotlight: Released from the brainstem and forebrain (nucleus basalis). Filters sensory inputs and amplifies the signal of whatever is the point of attention. The acetylcholine spotlight is what marks specific neurons as active during heightened alertness, strengthening those specific pathways.
• Dopamine and consolidation: Released during surprise, during error correction, and when we believe we are on the right path toward a goal. The dopamine flood increases plasticity. The practical implication covered in the Cheatsheet: attach dopamine to the process of making and correcting errors rather than only to the final reward.
• The trauma connection: Negative experiences deploy high levels of norepinephrine and acetylcholine to ensure the experience is remembered for safety. This is adaptive for survival and maladaptive when it produces intrusive traumatic memories. The connection to the trauma work in Therapy Time is worth exploring.

VI. The GO/NO-GO System in Learning

The basal ganglia architecture covered in the Habit section applies to learning focus.

The forebrain continuously plans what to do. Dopamine binding to D1 receptors triggers GO (action initiation); binding to D2 receptors triggers NO-GO (action suppression). Focused learning requires both doing certain things and not doing others (not checking the phone, not following the attentional drift).

Autonomic arousal makes us more prone to GO and worse at NO-GO suppression; this is why high-stimulation environments make focused learning harder. As mental fatigue accumulates, the action-suppression pathways (which are metabolically expensive) become harder to maintain, which is part of why focus degrades over a long session. The interaction between this and the 90-minute ultradian limit.

VII. Vision, Focus, and the Sensory Substrate

A Huberman theme: focus follows vision, and the sensory system can be deliberately engaged to support learning.

• Visual focus drives mental focus: When the eyes converge on a point, neurons trigger the release of norepinephrine, epinephrine, and acetylcholine. When eyes are relaxed and the visual field broadens, the system relaxes. 
• Blinking and alertness: When alert, eyes are wide and the blink rate drops. Reducing blinking can support sustained focus for cognitive work (though not for all tasks; sports differ).
• Auditory attention: Closing the eyes for auditory learning creates a cone of auditory attention. The superior colliculus links auditory, visual, and proprioceptive maps; aligning these sensory maps supports learning.
• The vestibular/balance plasticity gate: When we are off-balance and must compensate, the cerebellum signals deeper brain centres to release dopamine, norepinephrine, and acetylcholine to recalibrate. Balance challenge (within safety) may open plasticity. This is partly why children, who move in many dimensions and frequently challenge their balance, may learn faster than adults who move linearly. The implication: a novel physical challenge that pushes your orientation to gravity may prime broader learning. 

VIII. Recovery and the Diet/Supplement Questions

• Fasting and ketogenesis may support focus for some people through stable blood glucose and reduced post-meal sleepiness, though the effect varies and food preoccupation can undermine it for others.
• Electrolytes (particularly sodium) matter for people who drink coffee and experience jitteriness; the problem is often low salt rather than the caffeine itself.
• Choline donors (Alpha-GPC, ~300-600mg) have some evidence for power output and cognitive effects.
• Nicotine has documented attention effects through cholinergic transmission, with the addiction calibration covered in Discovery Basics.

The supplement material in the learning-optimisation space is oversold. A few interventions have reasonable evidence (caffeine, creatine, adequate electrolytes); most are marketed beyond what the evidence supports. The foundations (sleep, nutrition, movement, stress regulation) matter far more than any supplement. The Adderall question warrants particular caution: it increases alertness rather than focus, has abuse potential, and does not reliably translate into better performance.

IX. Reading Well

Reading is the foundational discovery skill for most knowledge domains, yet most people read the way they were taught in school: linearly, passively, without strategy.

The distinction between reading for entertainment, reading for information, and reading for understanding (Mortimer Adler’s How to Read a Book develops this). The Farnam Street reading framework (fs.blog/reading). The practice of reading actively (annotating, questioning, summarising) versus passively. The decision of what not to read (most books don’t warrant complete reading; some warrant rereading many times). The SQ3R method covered in Learning How to Learn.

In an environment of effectively infinite text, the scarce resource is not access to reading material but the judgement to select what’s worth reading and the discipline to engage it.

X. The Education Critique: (Heying and Weinstein)

A Hunter-Gatherer’s Guide to the 21st Century develops a critique of contemporary schooling.

The framing opens with John Taylor Gatto: the primary goal of real education is not to deliver facts but to guide students toward the truths that will allow them to take responsibility for their lives.

• What do we actually need school for? Given the rarity of formal teaching in other species and many human cultures, the question is worth asking. You need school to learn to read and write (these are evolutionarily new enough to require an educational supplement). School is useful for cell biology, written history, advanced mathematics, and for discussing texts with others, gaining exposure to unfamiliar ways of thinking, and learning to run experiments. But literacy, numeracy, and first-principles thinking are adaptive footholds; once you have them, you can teach yourself much without further schooling.
• Holding irreconcilable positions: School might teach what it sounds like when irreconcilable positions meet, allowing an insightful person to hold two irreconcilable positions in their own head at once. The value is immeasurable; it lets a person learn argument by arguing with themselves. Eastern traditions have embraced paradox more than Western ones; classrooms could be deliberately littered with paradoxes left in various states of interpretation.
• The metric problem: Memory and recall are easy to assess, so they become the metric chased by students, teachers, and schools. Critical thinking, logic, and creativity are far harder to teach and quantify, and at least as valuable. The trade-off is ubiquitous: a focus on memorised detail comes at the expense of the big picture.
• The fringe: School should reveal that fringe positions warrant exploration rather than immediate dismissal. Most fringe ideas are wrong, but it is from the fringe that paradigm shifts come. Betting against the fringe is easy and safe and usually shuts down dissent.
• School should not teach through fear: Fear is an easy mechanism of control. Using fear to keep children seated, silent, and still produces adults unable to regulate their own bodies and senses, unable to trust their own decisions, and likely to demand similarly controlled environments as adults.

XI. Higher Education Observations

• Tools are more valuable than facts: Their teaching approach: tell students they are not in competition with one another (and make it true); students learn more when they collaborate without a curve guaranteeing some fail. Break the “this is the time of day we are educated” paradigm by leaving the classroom and spending sustained time together, during which good questions show up at all hours.
• Intellectual self-reliance: The brick-in-the-wall model creates minds that are alike, ever less capable of generating or considering strange new ideas, outraged by confusion and uncertainty. The alternative: students game to be genuinely challenged, told when they are wrong, and taught to pose real questions and then sit in the not-knowing long enough to figure out how one might figure it out.
• The cost of looking things up: Answering “how” questions instantly with a few keystrokes may impede self-reliance. Pursuing “why” questions this way is even more likely to kill logical and creative thought. Before you look it up, think on it, walk on it, sleep on it, discuss it.
• The truth-versus-social-justice trade-off: A university cannot simultaneously maximise the pursuit of truth and the pursuit of social justice (as Jonathan Haidt has noted). This is a basic trade-off. It becomes important to ask what the purpose of a university is. The Heying/Weinstein position: the pursuit of truth must be primary. This is a contested claim worth engaging with from multiple perspectives rather than accepting or dismissing wholesale.
• Classrooms as sterile boxes: Removed from the world, they make it difficult to learn the things that cannot be taught but must be encountered. The proposed corrective: get students into nature and into the world, regardless of discipline, so they begin trusting themselves rather than taking others’ words for what is true.

XII. The Harari Bewilderment Question

21 Lessons for the 21st Century opens the learning question from the angle of preparing for an unknowable future. 

How do you live in an age of bewilderment, when the old stories have collapsed, and no new story has emerged to replace them? We have no idea what the world will look like in 2050, which makes it difficult to guide young people. Schools still teach children to cram information, which made sense when information was scarce and gatekept. Now we have information overload; the last thing schools need to do is fill heads with more. They should teach how to decipher fact from fiction and how to think.

The four Cs (critical thinking, communication, collaboration, creativity) plus the broader capacity to deal with change, learn new things, and preserve mental balance in unfamiliar settings. Teachers are often products of a defunct system and lack the flexibility the 21st century demands; the advice of most adults cannot be reliably distinguished between timeless wisdom and outdated bias.

XIII. Knowing Thyself

Continuing Harari. Most people don’t know themselves, so when told to “listen to themselves” they become prey to external manipulation. It is already hard to tell the difference between your own desires and the directives of marketing experts. The only durable response is to know yourself: spend time figuring out what your operating system actually requires, not what your smartphone, employer, government, or bank account want from you.

If you are content to let algorithms dictate your decisions, enjoy the ride. If you want to retain control over your life, you’ll need to understand yourself well enough to recognise when external systems are shaping your desires. The whole of The Human Operating Manual is, in one sense, an extended attempt at the ancient instruction to know thyself.

XIV. SMART Objectives and the Pragmatic Investment Plan

Practical learning-project frameworks from Andy Hunt’s Pragmatic Thinking and Learning.

• SMART objectives: Specific (narrow the goal to something concrete), Measurable (use actual numbers; if you can’t, it probably isn’t specific enough), Achievable (unachievable goals are soul-suckingly frustrating), Relevant (does this matter to you, and is it in your control), Time-boxed (without a deadline, goals languish). The driving-at-night metaphor: you can only see as far as your headlights, but you can make the whole trip that way.
• The Pragmatic Investment Plan: Treat your learning like an investment portfolio. Have a concrete plan with goals at different time horizons (next action, next year, five years). Diversify so you don’t have all your eggs in one basket; anything you learn has value even if not direct commercial value. Invest actively, not passively; get feedback and reassess. Invest regularly (dollar-cost averaging applied to learning time); create a ritual if needed.

The tension between this instrumentalised framing of learning-as-investment and the intrinsic-curiosity framing developed elsewhere in this section. Both have value; the investment framing supports sustained discipline, the curiosity framing supports genuine engagement. 

XV. Multiple Intelligences and Learning Styles

The existing material referenced Howard Gardner’s multiple intelligences and the visual/auditory/kinaesthetic learning-styles framework. 

• Learning styles: The framework that people have fixed learning styles (visual, auditory, kinaesthetic) and learn better when taught in their preferred style has failed to replicate. The 2008 review by Pashler and colleagues found minimal evidence that matching instruction to supposed learning style improves outcomes. The framework remains popular in education despite the weak evidence. People have preferences, but teaching to those preferences does not reliably improve learning; using multiple modalities benefits most learners regardless of stated preference.
• Gardner’s multiple intelligences: The theory that intelligence comprises multiple distinct capacities (linguistic, logical-mathematical, spatial, musical, kinaesthetic, interpersonal, intrapersonal, naturalistic) has intuitive appeal and limited empirical support as distinct intelligences. The capacities Gardner describes are real, but whether they are distinct “intelligences” or facets of more general cognitive ability is contested. Gardner himself has cautioned against using the framework as an excuse or as a fixed-trait model.

Both frameworks remain popular partly because they feel affirming (everyone has their own intelligence, their own style) and partly because they have been heavily marketed in education. The underlying observation (people differ in their capacities and preferences) is true; the specific frameworks built on it are weaker than their popularity suggests.

XVI. Mind Maps and Visual Thinking

Visual organisation of information to explore patterns and relationships. Start with the subject in the centre, draw branches for major subheadings, recurse for sub-nodes.

Mind mapping has moderate evidence for specific applications (brainstorming, overview of a domain, note-taking for some learners). The technique engages the spatial and holistic processing (R-mode) that linear note-taking doesn’t. The evidence for learning gains is mixed; the technique helps some people for some tasks. Tony Buzan, who popularised the modern mind map, made stronger claims than the evidence supports.

XVII. Play in Order to Learn

A theme that connects to the broader Discovery framing and to Rebranding Learning.

We have a cultural tendency to shovel information in and hope it proves useful later. The alternative: explore and get used to a problem before deciding on the facts, then return to exploration after absorbing the formal material. Anthropomorphism (putting yourself in the picture, imagining you are the system you’re studying) helps leverage experience. Play, in every sense of the word.

The developmental research on play as the primary learning mode of childhood (Peter Gray’s work), the loss of play in adult learning, the relationship between play and creativity, and the practical work of reclaiming play as an adult learner. The “build to learn, not learn to build” framing: gaining experience through doing rather than accumulating knowledge before acting.

XVIII. Problem-Solving with Polya

George Polya’s How to Solve It (1945) developed a framework for mathematical problem-solving that generalises broadly.

Understand the problem (what are the unknowns; what do you know; what constraints apply). Devise a plan (think of a familiar problem with similar unknowns; draw a picture; solve a related or simpler problem; work backward from the unknown toward the data). Execute the plan. Review the results (were all the constraints and data used; can the result be checked).

How Polya’s framework connects to first-principles thinking (Mental Model Basics), the role of analogy in problem-solving, and the practice of working backward from the goal. The framework is among the more durable contributions to the problem-solving literature.

XIX. Embedding Failure in Practice

The error-as-learning framing developed in the Cheatsheet, explored further.

A man’s errors are his portals of discovery (James Joyce). Debugging means solving problems, generally of our own making. “I don’t know” is a good start. The exploratory environment requires freedom to experiment with few repercussions, the ability to backtrack to a stable state, the ability to reproduce past work, and the ability to demonstrate progress through feedback.

You are least creative under time pressure (deadlines serve L-mode but not R-mode); once the pressure of failing is relieved, you tend to succeed because you can be attentive and observe. The “always be the worst person in the band” principle (surround yourself with more skilled people to improve dramatically). The relationship between psychological safety and the willingness to make the errors that learning requires.

XX. Focus, Defocus, and Managing Attention

The attention material from Andy Hunt, connecting to the broader focus work.

• Context switching is expensive: Multitasking costs 20-40% of productivity; each task swap requires dropping and reloading thought, and each interruption may take 20 minutes of recovery. Prepare for distractions; set distraction-free zones.
• Defocus to focus: The mental marinade: deliberately stepping away from a problem to let R-mode work on it asynchronously. Solutions often arrive during walks, showers, or sleep rather than during focused effort. The interplay between focused effort (L-mode) and defocused incubation (R-mode) is foundational to creative problem-solving.
• Worth exploring: the neuroscience of incubation and insight, the default mode network’s role in creative connection, the tension between the contemporary always-on attention environment and the defocused states that creative learning requires, and the meditation practices that train attentional control (see Mindfulness).

XXI. Open Research Questions

• The adult neurogenesis question. How much new neuron growth occurs in the adult human brain, and does it matter for learning?
• The transfer question. Does learning in one domain transfer to capacity in others, or is learning largely domain-specific?
• The vestibular-plasticity question. Does balance challenge genuinely open broader learning plasticity, and if so, how much?
• The micro-rest generalisation question. Do the 10-second gap effects found in motor learning generalise to conceptual and creative learning?
• The optimal forgetting question. How much should we try to retain versus externalise versus deliberately let go?
• The AI-and-learning question. What does sustained reliance on AI tools do to native learning capacity over years?
• The play-and-adult-learning question. Can adults reclaim the learning advantages of childhood play, and what would that require?
• The learning-styles question, resolved enough to say teaching-to-style doesn’t work, but the underlying individual differences remain incompletely characterised.

XXII. Future Topics

• Language acquisition (child versus adult, the critical period question)
• Motor skill learning in depth (the super-slow-motion and metronome protocols)
• Learning during major life transitions
• Learning across the lifespan (childhood, midlife, elderly)
• The relationship between physical fitness and learning capacity
• Learning in groups and organisations
• The neuroscience of insight and the “aha” moment
• Deliberate practice in creative versus closed-skill domains
• The role of emotion in memory formation
• Cross-cultural variation in learning approaches
• Learning disabilities and neurodivergent learning in depth
• The psychedelics-and-learning question (with appropriate caution)
• AI tutoring and personalised learning systems

XXIII. Resources Bridge

• The Huberman synthesis: Huberman Lab podcast episodes on neuroplasticity, learning, and focus. The protocols throughout this section derive primarily from these. Available at hubermanlab.com.
• The Heying/Weinstein education critique: A Hunter-Gatherer’s Guide to the 21st Century, with the calibration covered in Heuristics Basics.
• The Harari material: 21 Lessons for the 21st Century, with the calibration covered in Heuristics Basics.
• The Andy Hunt material: Pragmatic Thinking and Learning: Refactor Your Wetware for the practical frameworks.
• The Polya material: How to Solve It for the problem-solving framework.
• The reading material: Mortimer Adler’s How to Read a Book; the Farnam Street reading framework at fs.blog/reading.

XXIV. Cross-Links

• Discovery for the section overview
• Discovery Basics for the underlying neuroscience
• Rebranding Learning for the schooling critique
• Learning How to Learn for the meta-learning frameworks
• Learning Cheatsheet for the practical catalogue
• Resources for the reading list