Keep your eyes on the stars, and your feet on the ground.
Through NVGs on a long night watch, a man sees ten times more stars than his naked eye ever showed him. Ambition works the same way: one real look at how high it goes, and he never thinks small again. The rare ones climb but never forget their roots. They still shake the new guy's hand, still look people in the eye, and still remember every name that helped them up.