Have you ever replayed a game so much that you became a master at it?

[The Fury]

I've played lots of games but I don't understand the question really. I mean sure I can speed run Crash pretty well, or have little effort on Very Hard difficulty in Tekken but I don't think I've truely mastered any game.

However, Time Crisis. I got this on PS1 and played it enough that I knew where every enemy popped out. So when I went into the arcades I could complete it on 1 credit.