I once had the pleasure to run into Magic Johnson, who was at that time touring through Europe with a team of former NBA stars. He and two other guys were walking downtown and seemed a bit lost. I walked by and said "Hi Mr.Johnson, how are you doing" and he said he wasn't used to people calling him "Mr. Johnson", they usually called him Magic.
Then he asked if i knew a decent Italian restaurant in the vicinity and i escorted them to one. He asked if i was going to see the game the next day, of which i had no plans of visiting, but after this i couldn't resist. It's great to watch him play basketball, but it's even better to chat with the guy for a bit.
I'm not going to mention all the famous footballplayers i've run into over the years in clubs and bars, because i also got to see them play in the stadiums on a regular basis, but one encounter was kinda special. It was the time me and my friends bumped into Romario in one of the local nightclubs. I knew he was small, but when i was standing next to him he almost seemed like a dwarf. I shook his hand and it felt cold and tiny, like he just got out of a freezer or something, and he was accompanied by a blond chick who was almost twice his size.