Thomas walks up to Mama and hands her a scrap of paper with a smiley face drawn on it. "This is money," he explained. "You should take this to the store and buy something that costs $5 or $100 and then when you go to pay, give them this!"
"What do you think they would say?" questioned Mama.
"Probably 'Hey, this is paper money!'"
"And then what?" asked Mama.
"You say, 'But my son gave it to me!' and they would be like 'Fine, fine, fine'." After a small pause, he continued, "Or if it was a girl, she would say [voice raised to it's highest pitch] 'Fine, fine, fine'."