TITLE: How should someone remember theorems?
QUESTION [5 upvotes]: I'm reading a little textbook on axiomatic set theory, $296$ pages, and more than $270$ theorems are given (I counted them!), there is no way a person can remember $270+$ theorems (let alone the proofs!) just from one little book. How should someone study a textbook then? I mean, math at the end is just a list of theorems, proofs and definitions, but if it's impossible to remember them all, how should someone learn this subject? Should I only remember the important ones and if needed go back to that textbook? Should I write them down and keep them in a notebook? How do you guys do it?

REPLY [3 votes]: You say
I mean, math at the end is just a list of theorems, proofs and definitions.
I think that there is lot more structure than this suggests.
What I find helpful when working through a chapter of such a book is to sketch a graph of the relationships between the theorems: theorems are vertices, with arrows to indicate which theorems are used to prove each new result. The results you need to develop the big picture stand out; and you can ignore (for a bit) the others.