>>33
To be honest, mathematics can be very frustrating. I too struggle with it a lot more than I would be willing to admit. The best thing that has worked for me is as >>35 said, where I get different views of a single thing, from different sources and different subdisciplines (eg algebra, or analysis).
I might have failed to grant memorization it's value. Calculus is heavy on memorization: memorize the chain rule, memorize most derivatives, memorize binomial coefficients. But I just keep those things in a notebook. Maybe as you said, flashcards are just fancy notes.