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 £5 note in one hand and two pound coins in the other, then calls the boy over and asks, "Which do you want, son?", the boy takes the 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 the coins instead of the note?"

The boy licked his cone and replied,

Spoiler:

"Because the day I take the note, the game is over!

"

There could be a life lesson in there for the rest of us?