> Because mastery is, at the end of the day, converting an intellectual process into intuition, so you can go faster. Once a decision process is successfully ingrained, the intellectualized path is dead weight.

That's where you write a blog post, a company note, or a book if you got the time. The best proof of mastery is teaching because that's when you got confronted to the problems from another perspective (the other may not learn it as well as you do). And you won't have to repeat yourself that much if your arguments and process are written somewhere.