"He who is not courageous enough to take risks will accomplish nothing in life."
Muhammad Ali

"Whatever you do, you need courage. Whatever course you decide upon, there is always someone to tell you that you are wrong. There are always difficulties arising that tempt you to believe your critics are right. To map out a course of action and follow it to an end requires some of the same courage that a soldier needs. Peace has its victories, but it takes brave men and women to win them." 
Ralph Waldo Emerson

"Life shrinks or expands in proportion to one's courage."
Anaïs Nin

"A ship is safe in harbor, but that's not what ships are for." 
William Shedd

"I learned that courage was not the absence of fear, but the triumph over it. The brave man is not he who does not feel afraid, but he who conquers that fear."
Nelson Mandela

“Ever tried. Ever failed. No matter. Try Again. Fail again. Fail better.”
 Samuel Beckett