If you think your beaten, you are, If you think you dare not ,you not. If you like to win , but you think you can't , It is almost certain you won't  If you  think you'll lose , your lost, For out the world we 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 soon or late the man who wins, Is the man who thinks he can. 

:p ....... I think it means that to do choices you know you can do