Floyd Mayweather Jr was punching a speed bag in the gym at six. His often chaotic upbringing never distracted him from a burning ambition to be recognized as the best lb for lb fighter in the world. He has succeeded through iron discipline and a self belief that has never wavered. Mayweather was also at the forefront of business success, a world away from the image of the exploited boxer. It's an incredible story of an undefeated career - inside and outside the ring. Like him or loathe him, if you are into boxing you have to read this amazing story. There is only one Floyd Mayweather Jr.