Customer: “Hey, I want some Tylenol.”

Me: “For children or for adults?”

Customer: “For adults.”

Me: “At the moment, we only have the generic kind available. You know, paracetamol, also known as acetaminophen?”

Customer: “No! I don’t want any acetaminophen! Give me the other one!”

Me: “Ma’am, they are the same thing, just different names for the same ingredient.”

Customer: “Well, I just want the first one you named. Just don’t give me the other one.”