If you think you are beaten, you are. If you think that you dare not, you don't. If you'd like to win, but you think you can't, it's almost certain you won't. If you think you'll lose, you've lost. For, out in the world you'll find, Success begins with a fellow's will. It's all in the state of mind.
If you think you are outclassed, you are. You've got to think high to rise. You've got to be sure of yourself before you can ever win a prize. Life's battles don't always go to the stronger or faster man, but sooner or later, the man who wins is the man who thinks he can.
He can who thinks he can, and he can't who thinks he can't. This is an inexorable, indisputable law. - Orison Swett Marden