Who's the idiot now?

"If there are any idiots in the room, will they please stand up," said the sarcastic teacher. 

After a long silence, one freshman rose to his feet.

 "Now then mister, why do you consider yourself an idiot?!" inquired the teacher with a sneer. 

"Well actually I don't," said the student, 

"but I hate to see you standing up there all by yourself."