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.
That link claims that (1) he is incompetent and (2) he is liquidating the company. The two claims are not compatible. Nor does either constitute "looting." Looting is intentional behavior, not incompetence. If you do think liquidating a company is "looting," you could have just said so, rather than linking to an article and letting me figure out the behavior you meant. And there are a lot more examples of liquidation.
I don't think it's reasonable to expect someone who you disagree with about the meaning of a word used in an unusual context to know you disagree with them and mention it in advance.