I once got, from a finance guy, in all seriousness: "So, you're the CTO...I guess you must have a lot of gadgets at home...?"
My response was along the lines of "Actually, when I was in grad school I spent most of my time on theoretical computer science and artificial intelligence." A little obnoxious, sure, but he deserved it.
It means MS Word screwed you over again, this time by switching from A4 to Letter while you weren't looking. Damn Americans and their Imperialist defaults! :D
1) When he/she says they are a computer scientist, say "oh so you're like an IT guy? Because I recently got this virus..."
2) Call him a mouse jockey