I once sat through a seminar on rehearsal techniques (and jolly good it was too). The two guys running it said that most musicians don't stop as soon as a mistake occurs, and so end up 'practicing getting it wrong' more than they practice getting it right. The idea of practicing until you don't get it wrong is a really good one.
Think about band practice - how many times do you play a new tune before you get it right? 5, 6, 7? then you get it right.
Hooray, once more for luck, then move on. You got it wrong more times than you've got it right - so mathematically you're better at playing it wrong than playing it right.
I think that was the upshot of the seminar (I've missed a fair bit though), but it's stuck with me for ten years plus.
Cheers, Paul