This is a conversation that I had with a guy from the British Isles today in a cafe:
Guy: "Where are you from?"
Guy: "Boston, America?"
Guy: "No, you're not. You can't be American."
Guy: "Americans don't have hair that colour."
Me: "Have you been to America?"
Me: "And you didn't see anyone with hair this colour?"
Guy: "No, I didn't! Where are you from, really? Scotland?"
Me: "No. I'm from Boston."
Guy: (turns to his friend) "You're American - does she look American?"
Guy: "See? He's American. You can't be American."
Me: "But I am."
He bought me coffee afterwards, presumably to make up for the scene he caused regarding my nationality in a tiny cafe while I was trying to read.... so far, today has been odd.