Unlucky

I got into the elevator with a banker.
He pushed the button for the fourteenth floor, and we started to go up.
“Why is there no thirteenth floor?” I asked him.
“It’s unlucky,” he said. “Thirteen is unlucky.”
I took out my wallet, pulled out thirteen singles, and offered them to the banker.
He took it without question and stuck it in his pocket.
“Why is that not unlucky, and a floor is?”
The banker grinned. “It’s unlucky for you. I think I’ll have a coffee.”
I didn’t tell him that they were counterfeit.
But I told the Starbucks manager.