These two quotes personally resonate with me, they capture the importance of maintaining a clear vision in career and life.

It is well known the drunken sailor who staggers to the left or right with n independent random steps will, on the average, end up about √nsteps from the origin. But if there is a pretty girl in one direction, then his steps will tend to go in that direction and he will go a distance proportional to n. In a lifetime of many, many independent choices, small and large, a career with a vision will get you a distance proportional to n, while no vision will get you only the distance √n. In a sense, the main difference between those who go far and those who do not is some people have a vision and the others do not and therefore can only react to the current events as they happen.
Richard Hamming, The Art of Doing Science and Engineering: Learning to Learn

Rule 2 of Jordan Peterson's book Beyond Order: 12 More Rules for Life
Imagine who you could be, and then aim single-mindedly at that.

In the first scenario, we generate a path with 20 steps going in completely random directions. With no guidance or consideration of the vision, the steps often veer off resulting in a path that typically ends up far from the desired endpoint. By pure chance, the steps might head towards the right direction, sometimes even getting halfway there. But, in most instances, the path ends up somewhere completely unrelated to our vision.

For the second scenario, we introduce some guidance. Only 50% of the steps are random, while the rest are specifically directed towards the target. As a result, despite some steps going astray, the path generally trends towards the target. This consistent, albeit not exclusive, focus on the end goal significantly increases the chances of reaching, or at least getting near, the vision.