Customer: “Do you make curtains to order?”

Me: “Certainly. Do you have your measurements?”

Customer: *pleased with his cleverness* “I couldn’t find a tape measure, so I used this piece of string. The width is from the end of the string to this knot.”

Me: “Sir, this is a piece of elastic.”

Customer: “So?”

(He hands me the elastic string, which I proceed to stretch.)

Me: “Is your window this wide, or this wide, or this wide?”