You're clearly projecting in a massive way. I know plenty of people who do coke, some regularly some rarely, and they are among the nicest people I know, primarily because I don't associate with people who aren't generally nice.

Sounds like you were just associating with pricks and those pricks happened to use a popular drug.

;-)

just like the teachers who claim to know when students are teaching?

They all make the same speech but Somehow they never seem to know about it when 7 people in the class got a copy of test in advance and prepared answers. For every student who's bad a cheating and got caught, there is >15 that the teacher never knew about.