The greatest mistake is over-fixation on past mistakes. Learn from your mistakes, make amends, and never allow them to define your state of mind. The best American Football quarterbacks are those without “memories”. Yes, they simply forget the last bad play, for a great new play even though they have learnt from that broken down series. Across human history, more empires have been built and won through optimism than pessimism. You make the mistakes, and mistakes must never be your boss; put them where they belong: learn and forget past mistakes.