Shhhh. . . it's happening

I wasn't always like this. It's happened again. It didn't take long for it to escape from the classroom and into other aspects of my life.

My wife and I were at the movie theater and I had the strongest urge to 'shhhhhh' the people that were chatting. I've also noticed this urge during meetings, whether they be faculty or professional development classes/workshops. Idle chatter, the movie hadn't even started yet, they weren't interupting or keeping me from hearing anything - what's wrong with me? I don't want more behaviors crossing over, I have caught myself using the 'teacher voice' and have been called out for using it.
I've been able to control it, so far. I'm a little worried that one day I won't be able to and I'll shush a group of strangers. But should I care? Most of the time they would be justifiable shushes. I would not shush indiscriminately, unfounded shushing would only lead to anarchy, everyone shushing everyone else, a shushing nightmare, knee deep in shush. What is a shusher to do?