In fact, those outcomes are probably far more likely than the ones where twenty guns misfire twenty times in a row.
It's quite a bit less likely, but if quantum immortality changes the past (when you're on the border of life and death, it's clear the gun didn't misfire), then it would just keep you from running the experiment in the first place.
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.