If you think you are beaten, you are;
If you think 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’re lost;
For out in the world we find
Success begins with a fellow’s will;
It’s all in the state of mind!
If you think you’re outclassed, you are;
You’ve got to think high to rise.
You’ve got to be sure of yourself
Before you’ll ever win the prize.
Life’s battles don’t always go
To the stronger or faster man;
But sooner or later the man who wins
Is the person who thinks he can!

– Anonymous

Source: Inspirational Quotes and Poems