Thinking about this comment reminds me of an important point.
I do have a smartphone in my pocket and I can look up that information in seconds, quicker than I can type this post.
I don't recall exactly when I shifted that belief, but I think it was before I had a smartphone, which means that looking it up would probably take at least minutes, instead of seconds, which may be coloring me thinking now 'I should have just looked up some facts.'
Regardless of the status of beliefs about facts about the U.S. death penalty in particular, I agree there exist certain facts that are worth seconds looking into, that aren't worth minutes looking into (or any other appropriate combination of time increments)
Thanks for bringing this to my attention.
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.