Anthropomorphically forcing the world to have particular laws of physics by more effectively killing yourself if it doesn't seems... counter-productive to maximizing how much you know about the world. I'm also not sure how you can avoid disproving MWI by simply going to sleep, if you're going to accept that sort of evidence.
(Plus quantum suicide only has to keep you on the border of death. You can still end up as an eternally suffering almost-dying mentally broken husk of a being. In fact, those outcomes are probably far more likely than the ones where twenty guns misfire twenty times in a row.)
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.