I think it's one thing to be confident about being great relative to most people, and another to learn just how great the distance still is between you and "the best." I've definitely had this experience while learning things - as I move into say, the top 5-10%, I feel pretty good. And I'm confident putting myself there. But then I see just how far I have to go to get from 5% to 1%, or 1% to 0.1%, and it's the kind of thing that wouldn't have been obvious at all until I got to 5% because I'd have no idea what that difference even meant, and how hard the gap is to bridge.