If humans didn't have an amygdala — the two tiny almond-shaped nuclei in the temporal lobes of the brain — we wouldn't have any fear. We wouldn't know how to process risk, thereby letting us go hug a bear or climb the highest cliff.
But we do feel fear and in most cases, we're smart enough to run away or not do anything as a survival tactic. The problem becomes though when fear has us running away from the very things we wish to accomplish.
As they say, do something enough and the fear dissipates. The habit of practicing public speaking reduces presentation anxiety. Shooting hoops every day will make you more confident at the free throw line come game time.
The obstacle is the way
Risk-taking helps develop courage which helps engender competence. We shouldn't ever feel fear, but we should be able to manage its impact.
In doing anything more and more, whether it's through risk-taking, practice, or visualization, we can dull the senses. We can take things on without thinking about them or second-guessing ourselves.