Make something society wants. Don't focus on how much you want money. —Ray Dalio

Successful Bridgewater chief Ray Dalio of Bridgewater outlines his philosophy on self interest in his 123 page PDF manifesto "Principles", page 14:

Self-interest and society’s interests are generally symbiotic: more than anything else, it is pursuit of self- interest that motivates people to push themselves to do the difficult things that benefit them and that contribute to society. In return, society rewards those who give it what it wants. That is why how much money people have earned is a rough measure of how much they gave society what it wanted—NOT how much they desired to make money. Look at what caused people to make a lot of money and you will see that usually it is in proportion to their production of what the society wanted and largely unrelated to their desire to make money. There are many people who have made a lot of money who never made making a lot of money their primary goal. Instead, they simply engaged in the work that they were doing, produced what society wanted, and got rich doing it. And there are many people who really wanted to make a lot of money but never produced what the society wanted and they didn’t make a lot of money. In other words, there is an excellent correlation between giving society what it wants and making money, and almost no correlation between the desire to make money and how much money one makes.