It was at that point I said, “Mr. Stupid, why risk everything on one trade? Why not make your life a pursuit of happiness rather than pain?” That was when I first decided I had to learn discipline and money management. It was a cathartic experience for me, in the sense that I went to the edge, questioned my very ability as a trader, and decided that I was not going to quit. I was determined to come back and fight. I decided that I was going to become a very disciplined and business like about my trading.
— Paul Tudor Jones - Market Wizards