What this power is, I cannot say. All I know is that it exists...and it becomes available only when you are in that state of mind in which you know exactly what you want...and are fully determined not to quit until you get it.
- Alexander Graham Bell
You don't have to control your thoughts; you just have to stop letting them control you.
- Dan Millman
Forget past mistakes. Forget failures. Forget about everything except what you're going to do now - and do it.
- William Durant
Every defeat, every heartbreak, every loss, contains its own seed, its own lesson on how to improve your performance the next time.
- Og Mandino
To accomplish great things, we must not only act, but also dream; not only plan, but also believe.
- Anatole France