(I work at an optician’s office. We provide a service for customers who are diabetic where they can have a retinal screening.)

Me: “Can I help you, sir?”

Patient: *loudly* “I’m here for a diabetic rectal screening!”

(There is an uncomfortable pause while the patient digests what he has just boomed out to the whole shop in a very loud voice.)

Me: “Er…”

Patient: “I think I got that wrong.”

Me: “Slightly, sir.”