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 for. If you score only two out of three, eventually you will run into trouble.
The most lucrative careers are in areas where there is a lot of money sloshing around. At the apogee, this would be: hedge fund manager or investment banker. It also applies to any field where you are working for rich people or close to a torrent of money. Even if you get just a lick off the Popsicle, if there's enough sugar, it can be very sweet. That's why Willy Sutton robbed banks: because that's where the money is. He didn't rob orphanages or libraries.
If you want to position yourself to become rich, work in a field where money aggregates. If there's not a lot of money there, you will not become rich, however fulfilling the work may be in other respects. It also helps to be in a field where people are completely dependent upon your services. The highest-paid careers are in areas like medicine, accounting, engineering, law, and management.
Sometimes people say that you shouldn't become a (lawyer/doctor/dentist/accountant/etc.) because there are already too many (lawyers/doctors/dentists/accountants/etc.) ...