The American, who will defend his lightweight title for the fourth time at Yas Island in Abu Dhabi next month at UFC 112: Invincible against Frankie “The Answer” Edgar, is only the second fighter after Randy Couture to hold UFC titles in two weight categories.
And having already successfully defended his title three times against formidable opponents Sean Sherk, Kenny Florian and Diego Sanchez, Edgar, 28, is likely to have a tough task ahead of him.
“I always have fighting inside my head and heart,” Penn says. “It is not constantly in my head that I am a champion or a UFC fighter. I forget about that. It is very important to other people, and I am glad to have the support, but fighting is my passion. It is what I like to do.”
Born to a father with English and Irish heritage, and a third generation Korean-American mother in December 1978 in Hilo, Hawaii, Penn is the youngest of four children, three of whom are called Jay Dee, while the fourth is named Reagan. It is his status as the youngest that resulted in the nickname “Baby Jay” or BJ.
“I guess growing up, it was pretty much a normal life, as I got older I used to get into some fights but nothing unusual,” he says. “My dad took us to a couple of karate classes when we were young but we didn’t really get into it. My dad had been a black belt in judo but I never really cared about martial arts.”
As Penn got older, however, he started experimenting with boxing.
“There were a bunch of kids in the neighbourhood who used to come over and we would spar. We had a couple of pairs of boxing gloves, it just used to be friends on friends,” says Penn, 31.
When he was 17, fresh out of high school and with no clear career path ahead of him, Tom Callos, a sixth-degree taekwondo black belt, moved into the neighbourhood. On his first day in Hilo he placed leaflets around the area looking for judo and wrestling partners. Penn’s father, also named Jay Dee, spotted one and called to say that his boys would be interested.
Sean Sherk is knocked down by BJ Penn in the third round of their UFC lightweight championship fight at the MGM Grand Garden Arena in Las Vegas in May 2008. Penn went on to win. Eric Jamison / AP
Callos, who had started learning jiu-jitsu 18 months earlier, began teaching what he knew to BJ, his brother Reagan, and their friends, a couple of times a week at the Waiakea Recreation Centre. A few months later Penn accompanied Callos to San Jose, California, “because he had some business to do” and was introduced to Ralph Gracie, Callos’s former instructor.
“He [Gracie] saw that I could get somewhere and told Tom that,” he says. “When I came home my father said, ‘If you are not going to school, or working, in a couple of months, you are going to San Jose’, and that time went by with me hanging around the house drinking beer.
“My dad sent me out and said I should get my life together and go and do jiu-jitsu.”
Penn moved near to Gracie’s gym in San Jose and two years later earned his black belt in Brazilian Jiu-Jitsu (BJJ), a process that usually takes at least five years. He went on to win the 2000 World Jiu-Jitsu Championship.
“I thought it was cool but it was never going to be my life,” he adds. “I wasn’t born to be a UFC champion or a jiu-jitsu champion. If Tom had never moved to my neighbourhood it is hard to guess what I’d be doing.”
Penn met Dana White and Lorenzo Fertitta, owners of the UFC, while they were BJJ students long before they took over the ailing brand.
This meeting would later lead to Penn’s entrance into the Octagon on May 24, 2001, as a lightweight at UFC 31, where he would finish Joey Gilbert four minutes into the first round with a technical knockout (TKO).
“They ended up buying UFC and I asked them to get me in,” Penn says. “They pulled some strings, I was just going to try it one time, but the rest has become history.”
Penn went on to knock out the lightweights Din Thomas and Caol Uno before losing a championship bout to the then lightweight champion Jens Pulver.
When Pulver later relinquished his title Penn fought Uno again for the vacant belt at UFC 41, a fight that ended in a draw and saw the lightweight division suspended.
In 2004 Penn moved up a weight division to beat Matt Hughes, the five-time defending UFC welterweight champion, who will also be on the card at Ferrari World on April 10.
Penn left the UFC but returned in March 2006 as a welterweight, losing to Georges St Pierre, the current UFC welterweight champion, by a split decision.
On January 19, 2008, Penn fought and beat the lightweight contender Joe Stevenson at UFC 80 to become the lightweight champion – a title he is still successfully defending.
“I didn’t know it would take me this far,” he says. “It keeps me in shape, I enjoy the training and I like the fact that there are so many moves to master, and they all go together a bit like a puzzle.”
Despite the UFC grossing more annual pay-per-view revenue than almost any other promotion, its fighters gracing the covers of umpteen magazines and live events selling out, Penn has shunned the celebrity lifestyle to stay in his hometown of Hilo surrounded by his friends and family.
“I don’t know if it is important to me to live in Hilo, it is just very natural to me,” he says. “That is where I feel safe or comfortable, I can let my guard down and know I will be safe.
“Hilo is a small town. Most of the people I see are the people I went to school with, or I saw growing up. I get stopped in certain places but I spend most of my time in Hilo going to the gym and the grocery store.”
His daily routine involves waking up, going to the gym for training and then “jumping in the water to cool off” before heading home, to watch television, “hang out and take it easy”.
“My life is very structured around training and when fighting is finished I have a few weeks to a month off and I like to take it easy and clear my head. I enjoy my life,” he says.
On October 25, 2008, Penn became a father to daughter Aeva Lili’u. Being a father, Penn says, has changed his perspective on fighting.
“At first being a father and a fighter was hard. I used to think that she is only one-and-a-half, maybe at first I didn’t want to get hurt. Imagine if I got hurt really bad,” he says. “My partner watches me fight but I would prefer for them to stay at home so I know the baby is safe and then I can concentrate.
“When it comes to the fight there is nothing else to do. It can be dangerous if you don’t focus 100 per cent on what you are planning to do.”
Penn says he intends to continue fighting as long as he is winning.
“If I am not winning and take too much abuse then maybe I would like to stop right there,” he adds. “But then I have thoughts of fighting until I am 40 years old many times. I still don’t know what I am going to do when I grow up.”