Ask HN: What is one mistake you learned most from?

...so that we all can learn from each others mistakes. I'll go first: There was a time in my life where I was really unhappy with myself and my surroundings. And I projected that self-loathing onto others, being angry and cold to the people around me. Which in turn made things worse. Then one day I happened to talk to a teacher of mine and he just randomly mentioned that so much hate in this world comes from not accepting oneself and fight that inner conflict on the outside with the wrong opponent (namely, other people, instead of yourself). This really changed my perspective and I started to change my behaviour according to what I liked doing and hanging around with people I liked. Accepting that I do enjoy certain geeky things that in my old surroundings were frowned upon. This may sound very easy to do, but it takes strength. I guess what I am trying to say is that it is ok and good to listen to yourself and not others on how you should be and what you should like.