You build on failure. You use it as a stepping stone; close the door on the past. You don't try to forget the mistakes, but you don't dwell on it. You don't let it have any of your energy, or any of your time, or any of your space. If you analyse it as you're moving forward, you'll never fall in the same trap twice, which I can't say that I haven't been guilty of doing. But my advice is, if they're going to break your legs once when you go in that place, stay out of there.