The Little Book of Bulletproof Investing, Ben Stein and Phil DeMuth

Once you have acquired an education, you have to sell your services in the marketplace. This is not as easy as it sounds{…} Ideally, your career should be in that little sweet spot where three circles overlap: your passion, your talent, and the market. Or, the circles of what you love doing, what you are good at, and what people will pay you for. If you score only two out of three, eventually you will run into trouble.