With all the talk about brain trauma and how it effects a person's emotions, I think the story of Ike Ibeabuchi is relevant.
In the late 90's Ike was the heir apparent to the heavyweight championship. He had the skill and size to compete against Lewis and Holyfield.
Ring Magazine ranks David Tua the #2 hardest puncher in boxing history. Ike and Tua would fight in the most grueling and exciting heavyweight boxing match in history.
The fight holds the heavyweight record for punches thrown.Before the Tua Fight, Ike was a very religious and humble man. After the fight he was a completely different person and ended up in prison after beating up a hooker.
Many speculate that the Tua fight alone caused brain damage to Ibeabuchi and changed his personality completely.
Full Fight HD (Greatest Fight in Heavyweight History)