The Power of Doing The Job You Want, Not Waiting For It
Ask, ask, and ask again to be involved in tasks, projects and initiatives where ever you can. Keep asking and throw yourself into anything you can get your hands on, especially early on in your career. What this will do is force you to live outside your comfort zone and you will quickly see that you can do it; Then, it will suddenly become less of an issue with confidence because you will look back and say, "that wasn't so bad!"