#4

I had a long haired psych prof who one day told us in class that lsd is crystalline in structure and, pointing at all us other hippies, said one day when you are older it's going to turn solid and freeze up your brain!

We couldn't tell if he was kidding. He's also the one that taught us how to make a person catatonic, performed the famous German electrocution/loyalty test on us with ice water, and would periodically in a lecture let his voice get softer and softer until everyone was straining to follow what he was saying... and then he would scream!

He got most of us almost every time.