I'll begin graduate school next year and I am very impatient to learn new things such as theories, ways of thinking and so on (I enjoyed reading about category theory on my own and I find Galois theory very interesting for example).
However, during my undergraduate - and I am worried that it would do that again in graduate school - I was often stuck because I had to remember old results and/or had to figure out basic things - that I didn't study - (and exemple of this "basic things" can be found in my previous post where I was stuck with a simple set theory equality involving complements) and I find this very hard to manage (in terms of energy and time consumption). When I finally understand what I missed, I am discouraged (it breaks my motivation and I am very tired). Who knows how many of these things I forgot ? What if I have to use one of these tricks during an exam / while learning new material ? How can I better learn to avoid this situation in the future ?
I would like to know how do you react while dealing with similar problem (those who have good - or fresh - memory are not in this position). Do you have a way to quickly find the good reference (except SE) ? Does that break your motivation like me ? If yes, what do you do to "get back on the rails"?
Thanks for your answers.
In my experience, any material that you do not regularly brush up on, you forget. Sometimes partially, sometimes completely. You don't learn things once, then know them forever. You learn things once, then you remember the stuff that you need again and again. So don't get discouraged when you have to brush up on old material in order to understand new material, think of it as a chance to brush up on material in order to keep that material within your grasp. At some point, when you have had to brush up on certain material enough times, it will stick. This is part of a natural process where you forget material that you don't need, whereas the stuff you need is set in stone.
Always remember that the stuff you need is probably different from the stuff some other mathematician needs. So the process is unique to you, and in the long run defines the type of mathematician you become.