Our beliefs about what we are and what we can be precisely determine what we will be…. What we believe to be true, what we believe is possible, becomes what’s true, becomes what’s possible…. Many people are passionate, but because of their limiting beliefs about who they are and what they can do, they never take the actions that could make their dream a reality. People who succeed know what they want and believe that they can get it.

—Tony Robbins in Unlimited Power: The New Science Of Personal Achievement