[phish]

I think you're not being 100% honest with yourself. I would suspect that part of the reason you wanted to quit was because you didn't want to risk giving back some of that profit should the cards turn rapidly.
Aside from that, both Barry Greenstein and Phil Ivey have emphasized the important of taking advantage of your opponents when they're playing bad. When you're in a good situation, milk it for all it's worth. This is what really separates the good from the great: the ability to recognize when your game is off and have the discipline to quit, and likewise the killer instinct to recognize when your opponent is off his game and bleed him dry.