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.
And I have always told the patients when I talk to them. When they come around and say, 'What will you have to drink? Oh that's right you don't drink.' Just speak up and say, 'Of course I drink. But I just don't drink alcohol.'