I've not met many people the general population would consider a celebrity.
When I was young, Morris Day was playing drums in a band a close friend to the family had, but it was pre Purple Rain, so he was just a normal guy, although a bit of a nut even then.
I've met a few NHRA professional racers, and most of them are pretty cool. Tommy Johnson Jr is one of the nicest guys you will ever meet.
I've met a bunch of guys that are known in the racing world (drag and circle track), but arent really known by the masses.