What do you mean? I thought I made that clear. My opinion was well before 2011 and remained my go to comment until I read that article that there was no increase at all and that any claimed increase was purely media hype.
Your opinion about newsmedia was correct the whole time. This led you to ignore Mother Jones in 2012, but still your beliefs about the trends were correct for most of the time you held them.
What is the correct course of action?
Ignoring the newsmedia is clearly optimal. In particular paying attention to MJ writing on the same data set in 2012 would have produced the belief that spree killings had increased in 2006, an error according to your current MJ beliefs, though of course MJ doesn't notice the change. Maybe if you wait a few years, they'll convince you that nothing changed in 2011, only in 2015.
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.