- Mike Tyson found fame as the youngest heavyweight world champion in 1986
- The American now says: "I didn't like the person I was back then"
- Tyson, who spent time in jail, says being responsible is now his biggest fight
- At 47, Tyson hopes to use his life lessons to help young boxers
Mike Tyson has always relied on a fighter's instinct -- both in and out of the boxing ring.
The American was once idolized as the youngest heavyweight champion of the world only to be swiped off his pedestal by criminal convictions and drug addictions.
But at the age of 47, and long since retired from the ring, the provocative pugilist told CNN he is only now facing his biggest battle.
"Being responsible - that's going to be the most difficult fight in my life," Tyson told CNN's Rachel Nichols for her Unguarded series.
"I've never been responsible before. Just being a good husband and a good father. This is the biggest fight. This is the fight I'm taking with open arms."
Tyson, who is married to Kiki, his third wife, and has fathered eight children, is determined to focus on his family and a new generation of young boxers after a high-profile and controversial career.
Fatherhood for the man dubbed "Iron Mike" is framed against his own experience as a shy kid turned street fighter growing up in the Brownsville area of Brooklyn.
"Drugs, thefts, gang infested, crime infested," Tyson recalled of his childhood neighborhood. "No hope.
"To this day, I can't figure how from there, at that particular time, I made it to where I am now."
A teenage Tyson, by now spending time in a reform school, found an exit when his talents in the ring were spotted by respected trainer Cus D'Amato.
At the age of 18, Tyson turned professional and was soon undefeated in 22 bouts. Two years later, in 1986, the young American knocked out Trevor Berbick to become the youngest heavyweight world champion in history.
Tyson went undefeated for another four years but, with the benefit of hindsight, he now sees that heady era of fame and fortune very differently.
"I don't like that time in my life," Tyson continued. "I didn't like the person I was back then.
"Even with all that money and all that success I had, I didn't get anything done. My kids never saw me. I was a horrible father."
There were more life lessons for Tyson when in 1992 he was found guilty of rape and sentenced to 10 years in prison.
On his release, the Brooklyn boxer returned to the ring but controversy soon followed in the infamous "bite fight" against Evander Holyfield.
During the duo's second heavyweight title bout in 1997, Tyson chewed off a chunk of Holyfield's ear. He was later served with a one-year boxing ban.
But just as Tyson's reflections of the highs have changed over time, the same can be said of these low points.
Commenting on the so-called "bite fight" Tyson said: "Even though I was an undisciplined it was the only way I could get any kind of relief.
"I'm sad I bit his ear. I really am sorry because I like Evander, he's a good guy, a really good guy."
Of the rape charges, Tyson contemplated: "That may cause more controversy in my life, but that's not the lowest moment of my life."
In his interview with Nichols, he describes the tragic death of his four-year-old daughter Exodus in 2009 as his nadir.
The highlights for the 47-year-old Tyson, who is tentatively clean from his addictions, remain ahead.
"I'm accomplishing so much and getting so much done now as a human being, than I could've ever done back then in the prime of my fighting career," he explained.
"The best I am, and the best I've ever been, is right now. This is the best I'm going to ever be, compared to who I was before. "
Tyson retired from the ring in 2005 and has been fighting his way out of bankruptcy with a one-man Broadway show, cameos in Hollywood films and now as author of his autobiography "Undisputed Truth."
There is also a new project that may bring his career full circle. Tyson, under the umbrella of Iron Mike Productions, is now working as a promoter for a batch of promising young boxers.
"I'll give them the best advice I possibly can," said Tyson. "I'm just never gonna baby them. This is just what it is, you know.
"They have to be responsible, like I wasn't. I wasn't a responsible fighter."
Out of the ring, Tyson, with his trademark black tattoo arcing over his left eye, is looking for responsibility and perhaps even redemption at last.