According to dictionaries fear means; an emotion experienced in anticipation of some specific danger.
As human beings all of us have hade, and being rational, will have such an emotion.
We live in a world in which you can find nothing completely positive or negative, every thing that is related to mankind has both sides. i.e. fear has good as well as bad aspects too, but here I'm trying to take a look at bad aspects.
Fear is an obstacle to our achievements, you know better than me, we all have plenty of instances in this case, remember the first riding of bicycle of yours, could you?
The fear of falling, this fear causes stumbling, etc.
I believe that it is fear that stands in front of us as an obstacle and causes our failure or postpones our success.
Also there is another thing that some how has effects like fear, its called diffidence.
Here I have a question, how much do fear and diffidence overlap each other?