We all know that guy . . . the one that will give you a hundred reason why something can't be done, and not one single reason why you shouldn't try. It all boils down to the same thing--fear. For many people, the fear of failure is stronger than the desire to succeed.
But I would propose the idea that failure is not the opposite of success--it's a part of it. As John Paul Jones put it so perfectly, "It seems to be a law of nature, inflexible and inexorable, that those who will not risk cannot win."
So if you really want to accomplish something in life, get off your butt, and go bravely into the world determined to fail as many times as it takes to get it right.