Pack Mentality
When a group of people all do stupid stuff at the same time, like a bunch of idiots on a mission.
The whole class started screaming at the teacher just because he wore socks with sandals. Nobody even knew why.
My friends all ran into the street just because one of them saw a pigeon. They didn’t even care about getting hit by a car.
All the guys in the office started eating pizza at 10 AM just because one guy brought it in. Nobody asked why.