He's rude!

I go to USC, and I saw him on campus one day. I'm a smiley person and I tend to greet everyone that I pass. So I smiled and said "Good Morning" as I passed him. He gave me the dirtiest, why-the-hell-are-you-talking-to-me look. I mean sure he's a celebrity, but does that mean he can't speak to people. Even if he didnt speak he didnt have to give me an evil glare. Maybe he was having a bad day, but still, I try to smile back at people on my bad days.