What's your guiding North Star?

When reading through a profile of an investor who is really successful, one of their comments was around having a "North Star." He's a successful physician, has tended to many patients, and has continued to help millions more through developing medicines with Flagship Pioneering. 

You need to have a North Star: you need to know what is going to guide you through a crisis. My North Star is patient impact, and it has guided me through several career crises.

Have you ever given thought about what a North Star is to you? In a world which money and prestige are paramount (and don't count these out on these factoring into your north star, I just don't think they hold lasting value for myself), I was wondering how you think about having a "North Star," and keeping through that while trying to do the best you can. 

I would think that most people in this forum are trying to get a job in finance, and trying to "make it" in this world, and would count God, family, and friends part of their guiding north star.

Do you think that finance isn't part of your north star other than getting a pay cut and going home and tending to your north star? How do you balance that with the sheer number of hours which you spend in the day-to-day grind? Just a few reflective questions that I had after reading this article, and was curious about your thoughts.