Clever or dumb?

A boy was tired of hearing all his friends saying that he's a dumb. He decided to prove them wrong. He spent weeks studying a map of the United States, memorizing all the capitals for all the states. The next time, his friends started to say the same thing about him. Then he said "Hey, I'm not stupid or dumb. Maybe, I'm better than all of you. I can prove it here and now. Give me the name of any state and I'll tell you its capital without thinking."
"Vermont," someone suggested.
"Its capital is V." answered the boy confidently.