"It is necessary to the happiness of man that he be mentally faithful to himself. Infidelity does not consist in believing, or in disbelieving; it consists in professing to believe what he does not believe."
This quotation can be viewed in the context of a book
"Remind yourself regularly that you are better than you think you are. Successful people are not superhuman. Success does not require a super-intellect. Nor is there anything mystical about success. And success doesn't based on luck. Successful people are just ordinary folks who have developed belief in themselves and what they do. Never -- yes, never -- sell yourself short."