I wouldn’t have seriously asked him for a selfie while we were both trying to get through passport control after a 12-hour flight. It’s just a little bit of a bummer that I have no way of confirming that I actually did randomly run into Donald-Freaking-Knuth in the Munich airport. Doubly so because most people who I relate this story to have absolutely no clue who Donald-Freaking-Knuth even is, so it’s just completely lost on them.