This is a repository for major, life-altering mistakes that you or others have made. Detailed accounts of specific mistakes are welcome, and so are mentions of general classes of mistakes that people often make. If similar repositories already exist (inside or outside of LW), links are greatly appreciated.
The purpose of this repository is to collect information about serious misjudgements and mistakes in order to help people avoid similar mistakes. (I am posting this repository because I'm trying to conduct a premortem on my life and figure out what catastrophic risks may screw me over in the near or far future.)
One idea: Social power is contagious, so people want to associate with people that other people want to associate with. This leads to information cascades - one type of person has more power for some reason, so people want to associate with that type of person, so even more people want to associate with that type of person - and the "type of person" that this converges to gets called "normal".
Another idea: By caring about social norms, you signal that you care about not having people disapprove of you, which gives the group power over you - "I'll limit my sheep's grazing of the commons, because I don't want to look bad."