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.
“Don't wallow in brainstorming. Time spent fiddling with a business plan or filling up whiteboards with ideas is time that you could spend actually launching your business and seeing if the idea floats. Launching gives you real, solid feedback, instead of the imaginary 'what if' scenarios dreamed up ”