I’ve always found that memorizing proofs or actually doing the exercises (as opposed to taking time to understand the structure of the solutions to some of them, if the main text doesn’t already cover the representative propositions) hits diminishing returns, in most cases anyway, when you are learning for yourself. The details get forgotten too quickly to justify the effort, the useful thing is to get good hold of the concepts (which by the way can be glossed over even with all the proofs and exercises, by relying on brittle algorithm-like technique instead of deeper intuition).
I’ve always found that memorizing proofs or actually doing the exercises (as opposed to taking time to understand the structure of the solutions to some of them, if the main text doesn’t already cover the representative propositions) hits diminishing returns, in most cases anyway, when you are learning for yourself. The details get forgotten too quickly to justify the effort, the useful thing is to get good hold of the concepts (which by the way can be glossed over even with all the proofs and exercises, by relying on brittle algorithm-like technique instead of deeper intuition).