All of us have some kind of fear built in.
Some fear is silly or unfounded, while other fear is necessary for survival. At one time I was afraid of being in high places. Now I can not get enough of them. Why, you might ask? Because I exposed myself to heights enough that they were no longer a big deal. It took some time, but over time I challenged myself to get closer to the edge of a cliff and look down. In all fairness, I still will not dangle my legs off the sides, but I still have something to push myself towards.