On the proper harnessing of ambition..........

You can't let ambition get too far ahead of opportunity.  I've seen a lot people who had their sights set on a particular job or project, but the opportunity to actually get that thing was so slim.  Their focus on the small thing in the distance became a problem.  They grew impatient with where they were.  They didn't tend enough to the responsibilities they did have, because they were longing so much for something else, and so their ambition became counterproductive.  It's important to know how to find the balance—do the job you have well; be patient; look for opportunities to pitch in and expand and grow;  and make yourself one of the people, through attitude and energy and focus, that your bosses feel they have to turn to when an opportunity arises.  Conversely, if you're a boss, these are the people to nurture—not the ones who are clamoring for promotions and complaining about not being utilized enough but the ones who are proving themselves to be indispensable day in and day out.

-Robert Iger,  as culled from The Ride of a Lifetime:  Lessons Learned From 15 Years As CEO of the Walt Disney Company