Twenty Twenty Admission

I have just delivered a pizza to a guy in a sketchy part of town.

Customer: “You got change for a hundred?”

Me: “Sorry, no. I don’t carry more than a twenty in change.”

Customer: “How come?”

Me: “People are less inclined to rob me if they know I don’t have a lot of cash.”

Customer: “That’s stupid.”

Me: “Well, it keeps us safe.”

Customer: “Nah, I mean it’s stupid because I would still rob a dude for twenty bucks…”

Me: “…”

Customer: “…anyway thanks for the pizza.” *Pays with a twenty and closes the door.*

I’m suddenly worried about where he got the twenty he paid me with.