Programmers often discover solutions while explaining a problem to someone else, even to people with no programming knowledge. Describing the code, and comparing to what it actually does, exposes inconsistencies. Explaining a subject also forces the programmer to look at it from new perspectives and can provide a deeper understanding.
But isn’t that well known, even from school days? If you’ve ever explained something to someone you’ve recognized that by doing that you’re forced into overthinking the context, diving deeper into the subject.
Sure, teaching is one of the fastest ways to learn.
Also see SoDoTo. See one, Do one, Teach one.
https://www.eclathospitality.com/blog/career-management/use-the-sodoto-method-to-learn-anything