I ride that position alot and it never really got to me, but I went up with a friend that was doing her spotting for license, and when the door opened she screamed, I thought she was joking so I was laughing, but she never jumped the Cessna before. When we got down I asked her about it, and she said she wasn't sure why it frightened her the way it did, maybe it was just it being such a small plane or the fact that it was so much closer to the ground.
Just remember that you have your gear on, what's the worst that could happen?
A fanatic is someone that can't change his mind, but won't change the subject.