I’ve been pondering this question for quite a while:
Andy Rachleff told me that one of his best business lessons is that you learn far more from success than from failure, and that you should use success as a compass. Drive hard in the direction of what works rather than trying to shore up weaknesses. If something is working, more of that thing, or a better version is likely to work too. A better version of a failure is likely still going to fail.