Customer: "Erm? Them PC's I bought have you got a jackplug adapter for the keyboard and mouse?"
Customer: "It looks like I need an adapter for my keyboard and mouse, the only round one is this jack socket."
Me: "Are they PS2, green and purple?"
Me: "You need USB."
Customer: "I have some of them, will they work then?"
Me: [Close to tears] "Yes, plug them in and it will auto detect."
Customer: "Oh, OK."
These people have children you know, there's more of them in the world!