A quitter never wins-and-a winner never quits.

A quitter never wins and a winner never quits

You’ve got to be sure of yourself before
You can ever win a prize.

The only limitation is that which one sets up in one's own mind.

TELL THE WORLD WHAT YOU INTEND TO DO, BUT FIRST SHOW IT.This is the equivalent of saying "deeds, and not words, are what count most.

Whatever the mind can conceive and believe, it can achieve.