My biology lab instructor (she was a grad student at the time) started the first day of class saying "don't worry there are no dumb questions." About 30 minutes

My biology lab instructor (she was a grad student at the time) started the first day of class saying "don't worry there are no dumb questions." About 30 minutes into the lab someone asked a fairly unintelligent question and the instructor goes "well that was a dumb question.." I think she learned her lesson after that though. You gotta start somewhere!