Neil Gaiman gave an analogy for working toward a goal during his commencement speech that I really liked.
Imagine that your goal is a distant mountain. As long as any particular action brings you closer to the mountain, you are doing alright. If an opportunity arises, ask yourself if that opportunity will bring you closer to the mountain. If not, then say no.
But saying no can be hard, especially when the opportunity seems interesting.
Walk toward your mountain.
Arapahoe Basin in the Rockies of Colorado