If it's true the darkest hour comes just before the dawn, for George Foreman that darkness descended on his life some time during the steamy Zaire night of October 30, 1974.
The story of his bout with Muhammad Ali is now writ large in boxing folklore - how the seemingly unbeatable Foreman was stopped in the eighth round, crowning Ali's astonishing comeback to the world heavyweight championship after a three-year ban from boxing and a devastating loss to Joe Frazier.
To the victor went the spoils, to the vanquished pure misery; Foreman was left a broken man.
'When I lost the title to Ali it derailed me as a human being,' says Foreman. 'I had become full of hatred because that's what was needed to become champion of the world. All of a sudden that hatred becomes compounded, it turns back on yourself.
'I was vicious to become champion of the world and then I became vicious with hatred for myself and the world. You get tangled up. From a street fighter to heavyweight champion, I was not a human being, I was a mass of violence walking around with suits on and ties.''
Almost as astonishing as that 'Rumble in the Jungle' was the way Foreman found a way to pick himself up off the canvas, to reinvent himself and then - in 1994 - to win back that world title at the ripe old age of 45.