If we are startled or in a harmful situation we react and respond immediately. No hesitation just reaction. It is afterward that we get the shakes become afraid when speculating on what could have happened. We mark the key elements we should pay attention to such as stepping off the curb without looking and determine what we will do in the future to prevent the situation from occurring again. Check first.
When does fear occur?
All fear begins with 'what if'. We speculate about the future and play what if games. Certainly we need to look at potential problems and determine whether they will have an impact and more importantly what is the possibility of them occurring.
What we need to understand is everything about the future is predictive. It is our guess about what might or might not happen. We need to use common sense and not fear as our guide.
If our 'what if' gets out of hand then we can paralyze ourselves by fear rather than counting on our ability to adapt and modify to meet actual events. After all haven't we been doing that all our lives.