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.