It's just that I've never heard anyone talk about gun control and suicide, so it wasn't something that I ever considered related to the issue of gun control.
Heh. That's conclusive evidence that you've ever heard only one side of the gun control debate.
The anti-gun side widely uses "gun deaths" numbers which, as you just found out, contain suicides. The pro-gun side subtracts the suicides to get to actual "homicide using a gun" numbers. That's a very early and basic point in the debate.
So the blues, who are in favor of euthanasia, count suicides as a problem, and the reds, who are against it, do not? Ironic.
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.