I love the sentiment that Bezos expressed through this quote, and I sincerely hope to apply his advice to my career.

Having said that, this long-term way of thinking about happiness and regrets may conflict with human nature. The vast majority of us are incapable of predicting what will - or will not - make us happy:

http://scienceblogs.com/purepedantry/2008/04/22/happiness-pr...