Different things work for different people. Here's what works for me: If I think of what could go wrong, and prepare for it, I feel better. If the Mayan apocalypse comes while I'm traveling next week, there isn't a darn thing I can do about it. But if my wife and kids get snowed in the whole time I'm away, I know they'll have what they need, and that makes me feel better.

I do feel good when things go well and I don't need anything prepared, but I get a special frisson of joy when something I have "just in case" gets used.