"Once at band camp"(*), I have also heard from a friend whose uncle's niece's twin-half-brother boyfriend who once said that something "strange" happened that he could never repeat, shown anyone or get it validated.
So it scared the crapper out of me, and I have always believed in the "boogey-man" ever since...
(*) if you forgot, it is from "American Pie"...

Phi - I can verify what Brian said.