(A lady enters the store and gives me a raincheck that expired long ago)

Me: “Um, ma’am, this raincheck expired 90 days after you received it.”

Customer: “It doesn’t say that.”

(I point to where it does, in fact, say that)

Customer: (completely seriously) “That wasn’t there before.”

(I hand the raincheck back)

Me: “Would you still like to buy this product?”

Customer: “Yes, I have this raincheck for buy one get one free.”