It is often said that the best way to learn something is to do it. Simply reading, writing, or watching instructions does not engage us in the same way as the physical process of doing something.
If you want to learn the concept of pi, you can read a textbook.
Or, you can try to build a bicycle wheel, which is impossible unless you understand the concept of pi. Once you’ve done this, you will never forget about pi, unlike trying to rote memorize chapters from a textbook.
However, something else comes into play, and this is the reflection of what you’ve done. This is equally important. How did you do it? What could you have done better? Having the ability to review your own performance objectively — and not fool yourself — is incredibly important.
But it’s not easy. We are masters at spinning narratives to justify anything that we do. Most criminals, however guilty, do not honestly believe that it is their fault that they committed the crimes. They will invariably find some outside event that compelled them to act the way they did.
So it is not easy to get outside our heads and then look at ourselves objectively. One way that works for me is to write about an event as if it was a third person doing the various actions or considering specific decisions. This helps because I always find it much easier to advise others based on their situation than to look at my situation, and thus I use this strength to my advantage.
Regarding time and effort, we should try and equally split these between the doing and the reflection on the doing. If you play chess, spend as much time studying the game as you played. You’ll get a deeper nuance for your mistakes, the opportunities you acted upon, and those that passed you by. You’ll gain an understanding of patterns and build mental models that you will find helpful in future games.
And life is one big game.