> One of the best ways for me to learn, is to explain.

Kinda The Feynman Method[0] or even Rubber Ducky Debugging[1]. I found that teaching in grad school has immensely helped. Not only do you have to solidify concepts to a much higher degree but you revisit stuff too. I think there is a big difference between the level of expertise needed to be comfortable working with some knowledge vs what is needed to teach that knowledge. The former is much more personal. But when learning any topic there's always things you had to table, that you didn't answer, because you had to make general progress. But if you don't revisit these, then they always remain unknown. Revisiting often brings new insights and thinking that you probably didn't expect. Any time I've revisited a topic, even ones I know quite well and have revisited many times, I often find that there's still more for me to learn. There's infinite depth, so always keep your eye out.

[0] https://fs.blog/feynman-technique/

[1] https://en.wikipedia.org/wiki/Rubber_duck_debugging