When he was 12 years old, Muhammad Ali—known then as Cassius Clay—was robbed of his treasured red Schwinn bicycle. When he reported the theft to the police, he told the officer that he wanted to “whup” the criminal in retaliation. That officer was Sergeant Joe Martin, who professionally trained boxers in a private gym. Young Cassius showed up at Martin’s gym the next day and began his diligent, years-long training. The rest, as they say, is history.