The "famous" persons I have met have mostly been Musicians. The vast majority are wonderful folks. Every now & then I suppose, one might come across one as I did in a Jazz fest week some years back which my university held with the Musicians teaching various workshops, masterclasses, and of course, performing in concerts. One guy in particular refused to be onstage with any Musicians other than his band, refused to teach masterclasses or workshops and left that to his band members, refused to be a part of anything having to do with students or professors--would not allow them to speak to him, and was a total donkey's p'toot toward everyone, including many of his band members. After that I held little or no respect for Buddy Rich.
    Once, many years ago, my family band was playing backup on a tour with several 50's artists. They were delightful & fun people--except for one, who was deliberately quite nasty to all backup Musicians & many of the other headliners. Chubby Checkers said it was beneath him to converse with the "riff raff *#@%^+*>~#*#*!!"