Fear

Fear of failure is a powerful motivator.

It either makes you give it your Best.
Or
It makes you back down without even trying.

You get to choose which. And you gotta be wise while doing it.
But the question is: which of the two is the wiser choice??
What makes you think it's the first option??
There. Now there's fear of making a decision. And you start all over again.

And of course there's procrastination. In the hope that the solution will present by itself or to put it off till it's absolutely necessary.

Sometimes you have to just break the circle and do it. Abruptly. Firmly.
And you are free.

Till the next fork in the road.