Are you stupid? joke

College, during the first lesson. The professor of psychology greeting his new class. He stood up in front of the guys and said «would everyone who thinks he or she is stupid please stand up?».

After a minute or so of silence, a young man stood up.

«Well, hello there, so you actually think you’re a stupid?» the professor asked».

And the young: «No sir, I just didn’t want to see you standing there all by yourself».