Only one who devotes himself to a cause with his whole strength and soul can be a true master. For this reason mastery demands all of a person.
Albert Einstein
Of my own spirit let me be in sole though feeble mastery.
Sara Teasdale
Courage is resistance to fear, mastery of fear, not absence of fear.
Mark Twain
If people knew how hard I worked to get my mastery, it wouldn't seem so wonderful at all.
Michelangelo