Learning how to learn

post by Neel Nanda (neel-nanda-1) · 2020-09-30T16:50:19.356Z · LW · GW · None comments

This is a link post for https://www.neelnanda.io/blog/34-learning


  The 80/20 Rule
  Asking Questions
  Spaced Repetition
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The skill of learning things fast and well is phenomenally valuable. It serves as a force multiplier on almost everything you’ll do later in life, and I think it is worth invest a ton of effort into cultivating and developing. Getting better at learning is one of the most valuable things I’ve learned in my degree, and I think it’s a strong contender for my most useful and employable skill. And I think it’s significantly increased the chance that I can do something awesome with my life. I think that anyone who isn’t putting significant effort into improving at this, especially if you’re a student, is systematically screwing up.

This post is an attempt to outline my philosophy of learning, and the tactics/mindset which have worked best for me.

Learning is a useful skill in many different areas of life, with some general skills and some specific skills. I’ll outline many different techniques and approaches, and I recommend reading this post while keeping in mind your goals and contexts, and focusing on the ideas most relevant to you. A lot of my ideas are likely best suited to learning pure maths well, but they’ve seemed to generalise well for me, so I hope this post is of value! And many of my examples will revolve around students, since that’s my context, but the core ideas of effective learning generalise far beyond that. The world is complex and messy, and the process of becoming awesome is a constant process of getting better.

I’d also highly recommend the course Learning How to Learn as a usefully different perspective on good learning! (and from which I shamelessly stole the title of this post)


The most important insight, is that learning is a personal process. There are many possible strategies for how to learn, with different pros and cons. There isn’t a perfect killer app, to find your ideal learning strategy, you just need to try a lot of different stuff! Try something new, review it and see what worked well and didn’t, adapt it and repeat this process until it feels like it works well. This post is essentially a collection of my most successful experiments.

Expect to try many things, and expect most of them to fail. But this is totally fine! This is a textbook example of upside risk! You are going to spend the rest of your life learning new things. If you can marginally improve, that will stick with you for the rest of your life, while a failed experiment has a one off cost. Take a sacrifice in the moment to help your long-term self.

And notice when your current system is broken! If you’re perpetually confused, lose track of what’s going on, and never retain anything, this is a strong sign that it’s worth trying something different. Some things are just intrinsically hard, but you should be able to tell if you’re making progress

Further, a common failure mode is not realising how creative you can be with your learning style! A lot of students I see just absorb a default learning method of going to fast paced lectures and writing down everything they see on the board. And they stick to this style, no matter how confusing or inefficient it feels. But there are so many other ways out there! Ask your friends how they learn things. Ask the smartest people you know how they learn. Try something wild, that you’d never normally do. Don’t be afraid to deviate from the default.

Exercise: Pick something you learned recently, and think about how you learned. Now, set a 5 minute timer, and list other ways you could have learned it. Aim for as many as possible! And don’t confuse the feeling of it being hard to generate more ideas with it being impossible.


A significant mistake I see is not respecting the role of emotions, intuitions and introspection in effective learning. Our minds are phenomenally powerful computers, yet our system 2, the conscious verbal part we have access to, is just the tip of the iceberg. Our system 2 alone is utterly incapable of tasks like maintaining a conversation, which computers struggle with, yet our intuitions can manage just fine. A ton of valuable information can be found by paying close attentions to your emotions and intuitions, yet people often dismiss those as “irrational” and not worth listening to.

A few different ways this is helpful:

I find the technique of Noticing [LW · GW] to be super useful for getting better at introspection like this, and converting those vague feelings into something useful. I find this emotional awareness significantly drives my actions when learning something new, and triggers several times a day.

The 80/20 Rule

Another key point: there are a lot of things to learn, and a lot of details, and you only have finite time. You need to prioritise. The world is full of wasted motion, and will rarely prioritise for you. A ton of mileage comes from identifying how to get 80% of the value from 20% of the effort, doing that first, and then moving on!

Often the most important parts are getting a handle on the big picture and high-level understanding. Good prompts:

Getting the high-level picture is phenomenally valuable - it means that when learning any object level details, I can instantly see where they slot in, whether I care about them or not, what other ideas they connect to, how this could be useful in future, etc.

Another valuable skill is learning when to give up on something and when to move on. What things are not worth caring about? Notice when something is a BS magic trick, or a fiddly detail. I find that maths proofs are often 80% trivial algebra, and 10% magic tricks that are only relevant to that specific problem, and 10% key ideas that are used again and again. And I want to only remember those key ideas, all else is a waste of my time. Some good prompts:

This principles also applies to simplifying and compressing. After solving a tricky problem, or understanding a hard concept, compress your understanding to as few words and ideas as possible. Eg, challenge yourself to write down the key ideas of a course in <10 minutes. This pressure often forces me to identify the truly important ideas.

This also applies to the resources you learn from! Some resources are way better than others, and there is significant cognitive labour to learning from a bad resource. And sometimes it’s not even worth bothering! I recommend regularly asking “am I getting value from this?” and every hour writing down what you just learned. If you consistently write down nothing, there’s a decent chance you should change up how you’re doing things!

Two specific resources I’d highly recommend:


A phenomenally powerful way of learning something deeply is to teach it to somebody else!

One model I have of learning, is that I take in information in the format of language. But in my head, they’re stored in a more abstract, conceptual format. And the key challenge of learning is having a concept translated into language in the first place, and then translate from language into concepts, with as few errors as possible. And this will inevitably leave corruptions and holes, but these aren’t always clear (especially if I struggle to notice confusion or surprise!). Teaching forces me to convert this from concepts back into language, but using different words and framings, so it must go via the conceptual framework in my head. And this both reinforces those concepts, and make the corruptions and holes way more visceral. It’s easy to brush over something confusing when rushing through a textbook, but you can’t brush over it when explaining to somebody else.

Teaching also favours a high-level understanding - it’s really annoying to verbally convey fiddly details to somebody else. My aesthetic sense forces me to favour a coherent, high-level picture, prioritising the key bits and skipping over everything I can justify skipping out. And it’s much more obvious when an explanation is confused, and forces me to go back and understand it more deeply

There are a few different approaches to teaching, and they all have elements of these benefits:

When teaching, I find it most useful to focus on the structure, motivation and high-level picture. Thinking about how to efficiently convey ideas into a students mind when they lack context is an excellent way to structure the ideas better in your head.

I think teaching is also excellent, because teaching teaches you better meta-skills for learning well! Teaching and learning are two sides of the same coin - often there is cognitive labour that either the student or the teacher could do. And getting familiar with both points of view makes it clearer what these are, and ways you can fail to learn or fail to teach. I outline this perspective in more detail in my post on good teaching.

Asking Questions

I personally learn really well from other people. And my main tool for this is to ask questions (in both 1-1 or group settings). This is particularly salient to me, because questions are a key part of how I learn, but it feels like most people don’t even conceive of it as a skill worth cultivating or trying at. One of my general life goals is to surround myself with as many smart people as possible, and questions are the process by which I can move knowledge from their head to mine!

It’s easy to conceive of learning as a passive process, where knowledge is dispensed by a mentor and I just absorb it, but I think this is a terrible approach. Learning should always be active, as you compress the ideas into the conceptual language in your head, and notice errors, holes and confusions. And when learning from talk or a mentor, asking questions is the main way to actively engage! And if you are not constantly on top of things and processing information, I think you’re significantly and systematically missing out.

There are a few different mindsets for asking questions:

On a more meta-level, another way to use questions is by seeking feedback. As I outline in more detail here, seeking feedback is really important. It can identify your weak points, your misunderstanding, and your strengths. All of life is a trade-off, and you need to allocate your ability to understand improve accordingly. Feedback gives valuable information for doing this.

Feedback is also a great way to mine a mentor or teacher for information! You use their context to identify what you should most care about. And again, it’s much easier to correct than to teach!

Some tips:

Spaced Repetition

An underrated specific technique for learning well is spaced repetition. Education research has robustly shown that the best way to retain information is to be repeatedly and actively tested on it. And, the more times you’ve been tested on it, the longer it takes to forget it. So, if you review at the optimal time, the intervals increase exponentially, and your retention is good that entire time. So the total effort to remember something for the rest of my life just isn’t that high. And there is now software like Anki that can do this for you!

Rote memorisation tends to get a bad rap. I think it’s a valuable part of learning, because it ensures I have important knowledge at my fingertips. The difference between immediately knowing a fact and having to look it up is significant, because this removes friction. And friction is a significant hindrance on my ability to do things, be creative and make progress. Though, importantly, spaced repetition shouldn’t be used to achieve understanding. The ideal use case is taking something you already have a high-level picture for, and to ensure it sticks

A few tips for doing this well:

Anki isn’t for everyone, but if you haven’t tried it, I think there is significant value of information to trying it out! As Michael Nielson puts it, “Anki makes long-term memory a choice”. Don’t let long-term memory be something that just happens to you.


Overall, I think learning well is a phenomenally useful skill, and cultivating it should be a major life priority! The ability to learn well is a key force multiplier on anything else I might want to do. And it makes sense that most people underinvest in it - the short-term costs of doing anything different can be high, and the biggest payoffs are over the rest of your life. We have a systematic bias against this kind of longterm thinking!

Hopefully the ideas I’ve outlined in this post can serve as some useful starting points and prompts. I’d love to hear anybody else’s perspective on effective learning, if your methods and philosophy differ from mine!

To summarise some of the key high-level framework I’ve outlined in this post:

And remember, learning is a personal, iterative process! Try things, experiment, review how well it worked, and iterate! Your life should be a steady process of getting better at learning. And if you’ve been stuck in a rut learning wise, are you happy with that? Or could things be better?

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