In September 2019 I was interviewed on Ollie Lovell's ERRR podcast, along with Andy Matuschak, to talk about my work in the area of spaced repetition.
The result was a fairly in-depth coverage of many of interconnected areas including memory, self-directed learning, and a layered approach to accumulating knowledge over time. You can listen to the podcast here. It's 1.5 hours long, but you should be able to work out in the first 30 minutes whether or not you want to continue.