There are potential horrible things in the future, perhaps your future or mine.
Unthinkable illnesses, weird accidents, lightning bolts of misfortune at random moments.
If you decide to focus on them, you can fill your days with despair.
On the other hand, pretending that it's not stupid to text while driving, to swim during a thunderstorm or to ride a bike without a helmet is dangerous indeed. Our awareness of potential bad outcomes can cause us to make really good choices to avoid those outcomes.
So, what's the difference between being concerned about an asteroid hitting the Earth and being aware of how dangerous driving a Corvair at high speed is?
Here's the simple approach: How much would it cost you (in time, money, effort, distraction) to make yourself ten times less likely to be at risk?
It turns out that wearing a helmet is a cheap way to avoid a lifetime spine injury. You get a 10x improvement for very little effort. Knowing about the risk is really helpful, and any time you're tempted to run the risk, remind yourself of its implications.
On the other hand, the only way to becoming one-tenth as likely to die from choking on food is to stop eating anything but soup. Hardly worth it.
If there isn't a way to improve your odds, it's not clear why it's worth a lot of time or worry.
Worry is useful when it changes our behavior in productive ways. The rest of the time, it's a negative form of distraction, an entertainment designed to keep us from doing our work and living our lives.