Random person talking to me: "Are you an only child, or do you have siblings?"

Me: "I have one brother."

Dormouse: "What?!?" *yells* "YOU NEVER TOLD ME YOU HAD A BROTHER!"

Me: "Well, what do you think Uncle Dan is, then?"

Dormouse: "Well, I DIDN'T know he was your BROTHER!" *huffs, walks away*