Ask HN: How do you learn complex, dense technical information?

I think time plays a role. Trying to learn complicated stuff fast usually leads to not learning them well enough, in my experience. If I do so, jumping to wrong conclusions or applying a method on the wrong place/in the wrong way is almost guaranteed. So just keep reading, studying, picture yourself explaining it to a classroom, talk about it to colleagues and friends, engage on discussions about it online. Eventually you'll master the craft before you know it, and the good part is that such things may be on constant evolution and there will always be something new to learn. Just avoid being that one trick pony that knows a lot about one specific topic and that's it.

I am fairly sure this is not the optimal way, but I've been learning complex information/structures in passes.

For example:

- 1st pass - I consume the materials as well as possible, and apply my knowledge. Typically, I have to look things up, some things are unclear, I can't remember much. Applying the knowledge is quite difficult. That's ok.

- 2nd pass - I return to the materials, re-read much less thoroughly. I realize some things that I missed, or got wrong. I apply my knowledge, without looking information up again. This is, from my experience, when I get most of deeper understanding, but also where I learn most things that I remember long term.

- 3rd pass - if necessary, I can go through the materials again, just like in the 2nd pass. Diminishing returns start to kick in.

- (3+n) pass - diminishing returns start to manifest even in form of being bored with the materials, and starting to build up mental dislike for the materials/topics.

The passes are effective if and only if they are some time apart. Ideally, they are spaced in increasing time, i.e. 2nd pass is a day after 1st pass, but 3rd pass might be 3 weeks after 2nd pass.

The above has been useful for me, for example, when learning math or when I started to learn development way back. Note that in all passes, knowledge is applied. Without applying the knowledge, I learn much much less (though not nothing).

It also assumes that you have quite good theoretical source of information (e.g. a math textbook) and practical problems (e.g. math problems with correct solutions). If you're missing one or the other, e.g. if you're memorizing history lessons for your history 101 test, I'm not sure how effective the passes are.

I use a process I made up based on how suspension bridges are built: 1) literally an arrow is shot from one side to the other over the span the bridge is to occupy, and that arrow has a kite string attached; 2) the kite string is used to pull a thicker piece of twine; 3) the twine is used to pull rope and the rope is used to pull steel cable; 4) with the steel cable in place, the large scale bridge construction can begin.

In a software context, first just get anything operating in the target space you are trying to learn and develop. Then expand that minor nothing piece of software to be just slightly more capable, and observe what adjustments were necessary in your thinking to get that minor adjustment working. Repeat this process of small iterative changes with a formal review of what you're learning, and at some point you'll realize you have developed both a body of knowledge and a small framework for further work, and probably several ideas how to "fix" your mini-framework. Now spend some time trying to fix the mini-framework and use that to solidify what you've learned. And throughout this entire process: take notes, review the notes, and observe the scientific method in your notes: meaning write down a hypothesis, test it, write down the test results, write down you thoughts on the test results, and repeat. The writing down portion is important, as the act of writing it into notes forces fragment sentences to be formalized, completed and that can catch incomplete thought processes, which are critical, as they are the edge cases that also need to be handled.

I use the 1st, 2nd, 3rd pass methods but use SRS.

1st pass is high level concepts, 2nd pass is more details, and third pass is anything I still dont know.

This describes my process as well. I'd add that one of the huge benefits of the 1st pass is that it is low pressure. You just have to get through the material.

For example, I put off SICP for a very long time due to not wanting to put in the time for the exercises. Eventually I just decided to take a first pass, and made I through in a month. Second pass did the exercises.