Do you ever worry that you might go to hell after you die? Do you ever fear sleeping after watching a supernatural horror movie? Do you worry that your plane will crash when you take a flight?

I suffered from all of these worries when I was younger. I didn’t really believe that hell existed, but I still thought, “What if it does?” I didn’t believe in ghosts, but I still lay awake imagining one coming through my bedroom TV to kill me after I watched The Ring. And, despite the fact that I know a lot more about aircraft than most plane passengers, I still used to have nightmares about plane crashes in the weeks before a flight and anticipated disaster whenever I heard an unexpected groan or bump during a flight.

Worrying is a natural, human thing to do. It is an essential part of our survival mechanism. If we aren’t motivated to focus on real threats to our lives. . .