I was teaching the first of my back to back classes today when two of my students burst out laughing. I gave them a puzzled look, and one of them said, "This really weird looking guy just walked by." I glanced over my shoulder, and saw the disappearing back of, yes, a really weird student, one who just happens to be in the next class, heading there.
I turned back to the tale at hand and didn't say anything.
Adding about student weirdness: I really, really dislike when a student brings in an overpowering stale tobacco smell to the office... and then leaves it behind when they leave. Ugh, gross.