Have you ever encountered a celebrity, and if so, how was their demeanor?

I’ve passed by some of my country’s leaders (equivalent to the President in the US) while looking for a seat on the train. It happened like three times I think. But I obviously didn’t talk to any of them. One of them was talking to some members of parliament who were traveling with her. Another one was reading the newspaper. So… I’d say their demeanor was pretty normal.