I always get really scared on Coasters about, loosing my trainers whilst riding.
In the queue line for any Coaster, I always fasten my Shoes as tightly as possible, and spend half the time kneeling on the floor, making sure they won't fall off.
It's highly unlikely that my Shoes will catapult off during Air or Nemesis, but you can never be too sure :P.
I mean imagine the humiliation :(, you'd have to wear a plastic bag on your foot throughout the rest of the day, and everyone would stare...
I also hate the thought of loosing my Wallet or Phone :(.
But death-wise, I always worry that I won't be able to breathe, like on the launch of Rita, or Oblivion's drop. Then become unconscious, then die.
How irrational :P.