When I was told they were sending me Undisputed Truth, the new memoir by Mike Tyson, formerly the undisputed heavyweight champion of the world, I was expecting something a little lighter.

That may sound strange, since we’re talking about a man who has publicly struggled with addiction, bipolar disorder and anger management, not to mention being the behemoth behind eight-second knockouts. In recent years, Tyson has been having something of a renaissance. After a trio of self-effacing cameos in the Hangover movies, he followed up the popular Fox reality show Being Mike Tyson with a string of one-man shows called Undisputed Truth. Surely this was just a ghost-written companion to upsell the shows, right?

Wrong.

Far from being a work of image rehabilitation, it’s a brutal chronicle of violence, ambition, fear and abuse, all told in the distinctive voice of the fighter himself. Written with celebrity biographer Larry “Ratzo” Sloman, the book chronicles Tyson’s rise from his poverty-stricken childhood as a virtual orphan in the streets of Brownsville, Brooklyn, through his meteoric ascent in the world’s largest arenas and finally to his fall from grace—we’re talking drugs, alcohol, charges of abuse, multiple arrests and finally a 1992 rape conviction that sent him to prison, not to mention the loss of a fortune estimated to be north of $300 million. Undisputed Truth can’t even qualify as a cautionary tale, as a confessional epilogue details the August ESPN press conference where Tyson broke down, admitting that he was only six days sober.

It’s a hardcore read for sure. Tyson’s confessions have made headlines all over the world, and there are plenty to choose from. Fighting under the influence of cocaine and marijuana. Passing his drug tests using a fake penis called a “whizzer.” Threatening his ex-wife Robin Givens while Brad Pitt looked on, terrified. Whipping Mitch “Blood” Green in a street fight, breaking Tyson’s own hand. Stories so bad that Tyson, from his home in Las Vegas, admits that at one point he walked away from the book entirely.

“It was really difficult because Ratso first came over like four years ago to start getting these stories, and I was doing drugs,” Tyson says. “Ratso started asking some questions about my wife and some other things. Some awful things came out and I just couldn’t deal with it. That was the reason I was doing drugs, so I could hide from it all. I told him we’d start again tomorrow and I didn’t see him for two years.”

The stage show, written by Tyson’s third wife Lakiha "Kiki" Tyson, was captured by filmmaker Spike Lee and broadcast this month on HBO. The book digs much deeper into Tyson’s life, especially his boxing career.

“On stage, you get about 90 minutes and the book is over 500 pages, so I can go into more detail about my barometer and my psyche,” Tyson says. “This is all I know how to do. I never got to learn how to do anything else. All I’ve known my whole life is the roar of applause and the screams of people shouting my name. Good or bad, that’s all I know.”

It’s impossible to talk about Tyson’s arc without talking about his relationship with the trainer Constantino “Cus” D’Amato, the trainer who took in Tyson and told him at 13 years old that he would become the heavyweight champion of the world. Tyson was forged in D’Amato’s gym, built up to be a “god of war” that eventually evolved into “Iron Mike,” who Tyson says is dead now.

“That persona really meant something to me, because I had such low self-esteem back then,” Tyson remembers. “I really didn’t think I could do anything good because I was such a street rat. But I met this guy Cus and I had never met anybody who could get into my psyche like he did. Nobody could elicit that kind of fury and dedication from me. It was almost psychological brainwashing. Anything that man said I could do, I believed that I could do.”

It’s that fury that fans remember, for better or worse. Tyson was the gladiator who would attack foes and fans alike, feeling like if he killed someone in the ring that he might finally be taken seriously.

“It took a long time for that anger to surrender,” he admits quietly. “I didn’t know how to surrender. Cus kept that mentality until the day he died. He was hardcore. I never knew anybody like him the whole rest of my life.”

He doesn’t talk a lot about boxing in his stage show, except for a segment that explains the 1997 fight where Tyson bit off part of Evander Holyfield’s ear after being head-butted several times. But Tyson still spends a lot of time around the fights, recently launching Iron Mike Productions with partner Garry Jonas to promote fights, with events coming up in January in Minneapolis and Atlantic City. Although professional boxing hasn’t returned to the heights of his youth, Tyson still champions the sport.

“I’m sure that boxing will come back,” he says. “It has to come back. Even with all of my megalomania, I can’t believe that I could be the last fighter to have such an enormous effect on the public. There has to be somebody that comes around and dwarfs my antics and my skills and makes me look like a Boy Scout. That’s what evolution is all about. Guys have to come around who become better. People get better; they don’t get worse in life.”

I mention that I was surprised at how open he appeared in an episode of Being Mike Tyson filmed at an autograph event in Las Vegas. A laughing, smiling Tyson gamely pretends to bite the ears of fans, and dons a replica boxing robe, mugging for photos. The god of war laughs, loud.

“That’s the most requested photo that I get all over the world: bite my ear,” Tyson says. “I get it from everybody.”

As if all of this weren’t enough, Tyson is finding online fame with a new viral video, a Foot Locker commercial called “Week of Greatness” that finds Tyson returning Holyfield’s ear to him and Dennis Rodman buying a one-way ticket to North Korea. In fact, Tyson and Holyfield have long since reconciled their differences, appearing openly affectionate on Being Mike Tyson.

“You know, it was something that happened a long time ago, but I’m still glad we were able to put it behind us,” Tyson says.

It’s a lot of attention for one guy but Tyson is still a big, big man. He said recently that it was better to make great things than re-accumulate all that money and I asked if that was still true.

“Absolutely,” Tyson affirms. “I hope I can make some money someday but I don’t know when that’s ever going to happen again. I just enjoy making all these things and they’re going to last forever. Money don’t last forever, as I’ve proved.”

It’s hard to say if Tyson is a changed man, given his fast and furious history. But it’s pretty clear that he’s at least trying to look forward even as he looks back on a hard-hitting, complicated life.

“What can I do?” he asks. “I can’t lay down and die. I got to keep improving as a person. That’s life. You got to go through these hard adversities and get bogged down in these quagmires and you’re supposed to be a better person after going through your ordeals. I’ve reached that point in my life.”

Clayton Moore is a freelance writer, journalist, book critic, and prolific interviewer of other writers. His work appears in numerous newspapers, magazines, websites and other media. He is based in Boulder, Colorado.