My worst fear is something happpening to my wife or son. I know I could'nt handle that.
On a lighter note, I've had some scary stuff happen to me and I have to say it's put the fear of god into me at the time but made me a stronger person afterwards.
Never had a fear of flying until my first emergency landing-I seriously thought my no. was up! It left me spooked for a while and then I chilled out, relaxed and found myself on a 737 leaking fuel over Belgium a year later! Needless to say, I'm still here and we landed safely,thanks to a great pilot. It was a close run thing though. The best bit was my wife was with me and when I told her "Don't worry-I've done one of these before." She thought I had completely lost my marbles!
Another thing that bothers me is guns-I don't like them being pointed at me. I've been detained in various airports around the world at gunpoint, the worst experience being Nairobi airport. I local cop pointed a ready to fire AK-47 at my head because I was smoking outside the terminal building! Mind you, I managed to calm him down, so I guess these things can improve my communication skills! Also an important health lesson here too-smoking can get you killed!