I just heard this talk and had to share it. It's helped me understand why I achieve things and shows how focusing on money rewards is a recipe for failure not success. It's my mantra but it's explained so eloquently in this piece.
Simon Sinek: How great leaders inspire action - Simon Sinek (2009): "Simon Sinek has a simple but powerful model for inspirational leadership all starting with a golden circle and the question 'Why?' His examples include Apple, Martin Luther King, and the Wright brothers -- and as a counterpoint Tivo, which (until a recent court victory that tripled its stock price) appeared to be struggling."