1. "You become what you believe. You are where you are today in your life based on everything you have believed." --Oprah Winfrey, net worth of $2.7 billion First and foremost, you have to believe that greatness is possible. Many of the world's billionaires have shifted the way our world works, because they believed that they were capable of doing something that was previously impossible. Change is possible. Greatness is possible. But you can't do anything unless you first believe in yourself.

3. "The typical human life seems to be quite unplanned, undirected, unlived, and unsavored. Only those who consciously think about the adventure of living as a matter of making choices among options, which they have found for themselves, ever establish real self-control and live their lives fully." --Karl Albrecht, net worth of $25.4 billion Everything you do (or choose not to do) is a choice. Most of us think that life happens to us, but in reality life is something that we choose either by actively pursuing options and creating our own circumstances, or by blocking opportunities and limiting our beliefs of what is possible. You can choose the type of life you want to live.

5. "Getting the job done has been the basis for the success my company has achieved." --Michael Bloomberg, net worth of $22 billion Billionaires have grit and perseverance. Top performers work hard at hard things. And that means that successful people do the things that most people don't want to do, and that's why they get the job done.

6. "If I'm going to do something, I do it spectacularly or I don't do it at all." --Prince Alwaleed Bin Talal Alsaud, net worth of $18 billion Developing a world-class skill means that you have the capability to ignore everything else. You have to be able to focus on doing an incredible job or on ignoring it completely. Greatness doesn't come from simply "putting the time in" ... you have to put the time in with effort, energy, and resolve.

8. "The role of business is to produce goods and services that make people's lives better." --Charles Koch, net worth of $25 billion If your only goal is to become rich, then you're going to have trouble meeting your goal. However, if your focus is on making people's lives better, then you'll find that success comes much more quickly. 5. Charles G. Koch, 76
Company: Koch Industries
Net worth: $24.7 billion
Compensation: N/A

Charles G. Koch has been the chairman and CEO of Koch Industries — one of the largest privately owned companies in the U.S. — since 1967. The group’s annual revenue is more than $100 billion, according to Forbes.

9. "No person will make a great business who wants to do it all himself or get all the credit." --Andrew Carnegie, net worth of $298.3 billion (in 2007 dollars) Success unshared is failure. Our connections with other people are what give our work meaning. The things we do will only matter if they are shared with others.

10. "The ultimate definition of success is: you could lose everything that you have and truly be okay with it. Your happiness isn't based on external factors." --Tony Hsieh, net worth of $840 million So often, we push happiness out on the horizon of life. "Once I get this job, I'll be happy." Or, "If only I landed that promotion, then everything would be good." Of course, life doesn't work that way, and there is always another goal once we reach our previous idea of happiness. Money is important, but your life should never be built around it. Happiness comes before success, not after it.