What's the worst that could happen?

If you've been around me in the recent future, you have very likely heard me say something along the lines of "What's the worst that can happen?" I say it a fair amount, perhaps too much, even. Why do I say it? Because I like to think that I (at least, somewhat) try to live along those lines. What I'm trying to get at here is worry. While this question can be related to fear, worry, and I'm sure other emotions, I think that they share similarities but have mild differences.