Well, basically do what you love because you love it. Treat your occupation as a business, even if you are just an employee. That (at least to me) is a good way to think things through in their proper context.

If a person loves their occupation then that's great! But he/she still needs to treat it as a business rather than a mission for a higher cause (even if it was a mission for a higher cause) because without financial insight it gets hard to prioritize things.