" Ambition is the mainspring of life, but we must keep it wound up! Self-confidence is the balance wheel which keeps ambition moving at an even momentum. Enthusiasm is the oil with which we keep the human machine greased and in smooth running order. The well-organized, capable, and productive man is AMBITIOUS, ENTHUSIASTIC, and possesses plenty of SELF-CONFIDENCE. Without these, success is uncertain, if not impossible. "

― Jeffrey Gitomer , Truthful Living: The First Writings of Napoleon Hill