A young boy enters a barber shop and the barber whispers to his Customer,
“This is the dumbest kid in the world. Watch while I prove it to you.”The
barber puts a five rupee coin in one hand and two one rupeecoins(1+1=2) in
the other, then calls the boy over and asks,”Which do you want, son?”The
boy takes the two one rupee coins and leaves.”What did I tell you?” said
the barber. “That kid never learns!”Later, when the customer leaves, he
sees the same young boy coming out of the ice cream store. “Hey, son! May I
ask you a question?Why did you take two one rupee coins instead of five
rupee coin?” The boy licked his cone and replied,”Because THE DAY I TAKE
THE FIVE RUPEE COIN, THE GAME IS OVER

Moral: When you think  the other person is dumb, you may be making a fool of yourself.