Why?

How can I be so terrified of something I know can never happen to me? This never happens to anyone except on television, do I really need to worry? These are all things I've told myself years ago, but now I never question anything being possible to happen to anyone, no matter how young, old, no matter of nothing. This never leaves me alone, these are the thoughts that haunt me at night. Even when I think I've had the best day in the world, they still find away to bring voices into my mind and there's no way to run away from them.