to 
I do a lot more of the exercises in books I read now than I used to. Maybe in another decade I will actually wade through the proofs instead of skipping over them.
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And another decade after that, you can try deriving the proofs yourself! This may be one of the most effective ways to learn math: read a textbook, close the book when you come to a theorem. Continue after you prove it. Obviously takes a lot of time and patience.
I would recommend making uses of the worked example effect based on cognitive load theory w/ spaced repetition.
