One way that fear can keep us from achieving what we want:

We often hold ourselves back by using limited perceptions to imagine what our obstacles might be, but in reality we have no idea of what we will actually encounter in any endeavor. We think that we understand how the game is played, so we can, to some degree, know how things will carry out, but all we really have is an idea of what we think should happen, a script that only exists in our minds. Funny how the things we assume will challenge us are very often not the real obstacles; but other things come, things we can’t predict or even imagine until we actually take the leap. You have to understand that you will find a new way to solve the problems that you couldn’t even conceive were coming; and that you will forge who you are exactly by carrying out a unique struggle in that area of life in which you are choosing to play. So don’t hold yourself back from playing—you will get more out of life by not allowing your unfounded fears to guide you.