Before you change your thinking, you have to change what goes into your mind.
Regardless of your lot in life, you can build something beautiful on it.
For every sale you miss because you're too enthusiastic, you will miss a hundred because you're not enthusiastic enough.
Fear is the darkroom where negatives are developed.
Of course motivation is not permanent. But then, neither is bathing; but it is something you should do on a regular basis.
The greatest single cause of a poor self-image is the absence of unconditional love.