What is something you used to believe, preferably something concrete with direct or implied predictions, that you now know was dead wrong. Was your belief rational given what you knew and could know back then, or was it irrational, and why?
Edit: I feel like some of these are getting a bit glib and political. Please try to explain what false assumptions or biases were underlying your beliefs - be introspective - this is LW after all.
Done out of conscious self-interest, rather than for moral reasons. (I'm well aware that our moral reasoning was optimized by evolution for self-interest; nevertheless, I think the distinction is real).
I'm not sure the distinction is real.
Do you have any examples?