You all cant expect anybody you dont know, celeb or not, to just act completely normal and buddy buddy when they have some random person come up to them and say hi. At the same time, I wouldnt think it hard for them to be kind in return, but we shouldnt go all extreme one way or the other. Just like anybody else, famous people do have bad days or just times when they dont know what to say. I met quest up at harvard early in the year, and thought he was a very nice guy and completely accomodating. There is only so much a person you dont know can do to act like they are really interested in everybody they meet.