Dumb kid?

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 rupee coins 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?" says the barber, grinning. "That kid never learns! " 

Later, as the customer is leaving, he sees the same young boy coming out of the ice cream store. 

He calls to him. "Hey, son! May I ask you a question? 

"Sure," the kid says.

"Why did you take the two one rupee coins instead of the five rupee coin?"

The boy licks his cone and replies, "Because the day I take the five rupee coin, the game's over."