"Learning from our mistakes is critical for improving, but even I don't have patience for ranking my regrets. Regret is a negative emotion that inhibits the optimism required to take on new challenges. You risk living in an alternative universe, where if only you had done this or that differently, things would be better. That's a poor substitute for making your actual life better, or improving the lives of others. Regret briefly, analyze and understand, and then move on, improving the only life you have."