The best programmers ever are humble, they know their worth, and don't have to show off. I'm sure people around you will appreciate humility, so if you want to push your limits, why not helping that guy who just joined the team and seems a bit lost?
Depends on your definition. The most famous programmers often aren't so humble. If you're working for other people, being quiet is bad for your career path unless you have a rare manager.
