So let's visualize my situation with the help of a stairwell. It has 20-30 steps leading to the top floor. I'm standing at the bottom looking up. But I'm having trouble climbing them. Why? Because, instead of focusing on the first step up, I'm consumed with the steps that are higher up. I'm thinking "Wonder what the view would be like from step # 7" or "Which foot will land on the 30th step if I start off with the left foot on the first step?"
See? It's paralyzing. Imagine this scenario when the place is dark and splashes of light fall on steps towards the top of the stairwell. Then it's "I can never get that far up!" "Maybe I should stay where I am till it's bright" followed by "Why didn't I start just an hour earlier when there was light?" "Why did I lose all this time looking for my favorite pair of slippers?"
Point is...in any of these cases, the focus is on the wrong things and not on taking the first step. Even in the dark, the first step means success. Means, when the lights come back the view will be a tad better and the top of the stairs just a tad closer.
Set goals, fine. Just don't let idle minds play.