[harperlee]

I believe this is a great answer. One way of doing that, in my opinion, is writing blog posts explaining things. When I do that, I invariably end up doubting about some things that I write, doing small experiments to see whether something is always true, etc. So in effect, the act of talking/writing/explaining something, makes you analyze what you think you know, and search for where that ends, how that breaks, etc.