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.
“Life is too short to worry about anything. You had better enjoy it because the next day promises nothing.”
“The human brain starts working the moment you are born and never stops until you stand up to speak in public.”