Lots of people are like that. I had a friend that could play Doom and Quake all day long, but have him stand over my shoulder and watch me play, instant upchuck.
I'm a little that way with cars. I love driving and driving games, but if I'm in the passenger seat, it takes some effort to keep from getting nauseated.
But games, never had any issues with (although Descent screwed with my brain for about the first 2 months I played it).