"test your explanations! ...running an explanation by a few people who don’t already know the concept helps to catch incorrect assumptions I’ve made."

I love this.

As I get more skilled with a thing I think I can have more confidence that I'm doing it well and according to best practices up front but that my highest level of confidence comes from employing the thing in practice and observing the results.

That could be deploying code to prod with monitoring, having another dev review my code to see if it's readable, having users interact with my system while I observe, or in this case seeing if someone can read my explanations and understand the ideas I'm trying to communicate.