One thing I learned about ten years ago is that when I need to memorize things, flashcards work really well for me. More recently, because I often bounce between many technologies, I have been making flashcards as a way of bringing me back up to speed after I’ve been away from a technology for a while.
The image shows one example of this, where I created a stack of flashcards to help me remember/relearn Android, which I haven’t used in several months. In this case I also have my Android cheat sheet to fall back on, but even then I still like using the flashcards. I think the theory is that rather than reading something passively, flashcards force you to try to recall something, and that’s a much more active way of using your brain and memory.