@Rovine I think retention is a wholly personal experience. Some are visual, some auditory, some spoken learners. But besides that there are subtle details that are important.
What I can say is this one universal fact, learning is **all** about association. Memeorization as a pure practice is a failed practice, if you are doing it, stop. Instead try to take the things you want to memorize and thing about how it associates with other things, even if those things arent important. For example think about how a word might sound like some other word, and what those words have in common, or other things. Just anything that creates arbitrary associations in your brain.