I'll start:
"Your voice is too low. It's not your fault." - science teacher
"Your need to scroll does not supercede our need to stay alive." - art teacher
Also, here's a funny interaction that happened today (with fake names):
Chem teacher: Caleb, Jack, you missed the whole lecture!
Caleb: I had a dentist appointment and Jack was my dentist.
Martin: That's your excuse? Really?!
Me: Was Jack a good dentist?
Caleb: No. He gave me anesthesia for no reason.
Jack: I saved your cavities!
Caleb: I don't have cavities!