My interest is in the future because I am going to spend the rest of my life there.” Charles Kettering
“To achieve greatness, start where you are, use what you have, do what you can.” Bernard Shaw
“If we did all the things we are capable of doing, we would literally astound ourselves” Ralph Waldo Emerson
“If you can imagine it, you can achieve it; if you can dream it, you can become it.” Thomas Edison
These four quotes should get you started on your journey.
In fact commit all above to memory, or print them out onto little cards, carry them in your wallet, and refer to them daily.
Cheers and enjoy