I poked my head over and said "You mean Randall Munroe?" Yeah, they meant him but "Well I wouldn't have known who that was..."
I didn't have the heart to tell them I was in Cambridge on Sunday, or the other brushes with greatness I've had in the XKCD department.
Though I was tempted to wash my spray-painted t-shirt to wear into the office tomorrow, I also resisted there.
I must be getting mature or something.