Wallace Stegner said this quote
“ Ambition is a path, not a destination, and it is essentially the same path for everybody. No matter what the goal is, the path leads through Pilgrim's Progress regions of motivation, hard work, persistence, stubbornness, and resilience under disappointment. Unconsidered, merely indulged, ambition becomes a vice; it can turn a man into a machine that knows nothing but how to run. Considered, it can be something else - pathway to the stars, maybe. ”