Fear of unknown things isn't rational because we are emotional beings above all else. Thus we will develop a fear of flying or visiting the dentist based on preconceived ideas about how things will turn out and not on reality based thinking.
It doesn't matter how statistically safe flying is; we will instead drive even if the chance of dying in a car crash is higher.
Most of us live our lives imagining worse case scenarios that don't happen and would benefit from being braver. At the end of their lifespan most of us regret what we didn't do instead of what we did.
This is true for the overwhelming majority of us.
No, don't jump out of an airplane without a parachute but from where I sit now, i can tell you that the vast majority of my worst case scenarios have been completely dispelled.
