Films for Action: Richard Feynman's technique for learning new things
Here's a simple technique for learning something quickly - and I find, also deeply. If you can explain something in layman's terms to an intelligent novice, you will have assimilated the subject in a deep way.
By the way I was trained to teach meditation this way - avoiding spiritual jargon and Sanskrit terminology - and found it marvelously effective.
It is the process of thinking about an idea while teaching it that make the method so effective. Once you can explain an idea with simple language and create graphic analogies, you have deeply understood it and will remember it for a long time.