Neither did Holmes’ psychiatrist. Neither did Cho’s English Professor. Neither did Hassan’s co-workers.
On the prepper threads there is a thing called “normative bias” or something. A thing in our brains that, when thinking about how bad a situation could get (say no electricity for 6 months) copes by saying “Well that could never happen here.”
I’m guessing it is the same thing here. “Well sure he talks a big story, but no way he would ever DO something that crazy.” I know they teach the kids in school when it comes to a classmate talking suicide to let someone know.
But then there are numerous threads right here on FR that would garner attention.
“Turn Mecca into glass”
“Hang the child molester over a fire”
“Give me 5 minutes with him in a dark alley”
Etc.
Probably not the same thing, but...
I suppose means and ability factor in too.
My daughter says how she hates everyone at her school. Doesn’t mean she’s going to shoot the place up. (In fact, she is going to the junior college for her senior year as a solution to the problem.)