Little Johnny went to the mall and rushed into a toy store to buy a toy plane. He handed the cashier Monopoly money and headed for the exit.

The shopkeeper called out, «Hey, kid, this isn’t real money.»

Johnny kept walking, not saying a word. The shopkeeper repeated, «Excuse me, that’s not real money!» Still, Johnny didn’t stop.

On the third call, Johnny finally turned around and said, «What?»

The shopkeeper patiently replied, «I’m afraid this money isn’t real.»

Johnny looked at the toy plane in his hands, then back at the shopkeeper, and said, «Well, this isn’t a real plane, either.»