[danielbigham]

Something that I started doing recently is to create a "30 second summary" of each important concept, consisting of text and diagrams. I then record a 30 second video where I narrate, using good intonation, the 30 second summary. I also create a hyperlink from the summary to my notes of each prerequisite concept.

This serves three purposes:

1) The act of teaching is one of the best ways to solidify a concept in your mind. It forces you to have a good understanding of it, and forces your mind to produce a good internal organization around concept.

2) It usually takes a while to write + diagram a good summary, and takes a number of tries to get a smooth recording of you speaking the summary (Example: https://www.youtube.com/watch?v=rHc-bog1hhE). All of this "repetition" / time spent with the concept makes it easier to remember.

3) Sooner or later we realize that remembering everything is impossible. Given enough time, concepts will decay in your mind. In the long term, one of the most important things for you to optimize is the speed at which you can re-create your mental model of a concept. Having these 30 second summaries, complete with links to prerequisite concepts, allows you to re-build your mental model of a subject area extremely quickly in the future in a just-in-time fashion. Just like a smartphone is an "extension" of your brain, a note system like I've described here is like an extension of your memory.