If it came earlier, he can't be sure.
Growing up poor in one of the biggest agricultural centers in the United States, Diaz has what on the surface reads like a classic fighter tale: A significant portion of his life was spent without the presence of his father; he developed a reputation for fighting 18 year olds when he was in the eighth grade; the bullied kid from Stockton, Calif., was more truant than student.
But really, Diaz says even if he hadn't experienced those hardships, something, perhaps the same substance that forced a 7-iron into Tiger Woods' hands, would have driven him into prizefighting.
"Nobody is going to understand that sort of thing: not your friends, not your girlfriend, not your mom, not your family," says Diaz, who steps into the cage against KJ Noons for the vacant EliteXC 160-pound title Saturday in Corpus Christi, Texas. "It's my head that's smashed into the mat."
Eight years ago, Cesar Gracie (Pictures) traveled to Stockton, where Steve Heath told his instructor there was this kid he had to see. Inside the old Animal House Gym, Diaz found Brazilian jiu-jitsu, and for him there was nothing else in the world worth doing anymore.
"Even though he was green, you could see him thinking while he was training, like technically trying to do stuff instead of spazzing out," says Gracie of a then 16-year-old Diaz. "He was always more about the technique, and I was always impressed by his natural ability at the time."
To hear Diaz tell it, jiu-jitsu changed his life. He wasn't doing much of anything, just running the streets, drinking, causing ruckus. BJJ offered the discipline, structure and challenge he needed to keep from getting bored and avoid serious trouble.
"I didn't have a job before that," Diaz says. "I was only 15, and I didn't go to school. Most 10 to 15 year olds go to school. So when I turned 16, I started training religiously like it was my job."
Before long Diaz was fighting professionally. After making $700 in his first fight, he quickly moved through the California MMA scene and found himself in the UFC, again living life in the trenches rather than learning through theory.
Highs and lows marked Diaz's tenure in the Octagon. He bounced around a bit, winning more than he lost, before getting a shot at dropping 10 pounds to 160, where he met PRIDE champion Takanori Gomi (Pictures) and delivered one of the best performances of 2007.
It was in the aftermath of that fight, however, that Diaz cemented a name and reputation.
Having tested positive for what the Nevada State Athletic Commission said was a significant concentration of THC, the active ingredient in marijuana, Diaz sat out half a year while serving his suspension. More importantly, the commission made Diaz the first victim of regulations that allowed it to strip wins from fighters who test positive for banned substances.
For Diaz, the disastrous turn in the face of what was his most important and electric in-ring triumph marked yet another moment he felt bullied.
"To him, sometimes, life is representative of that bullying," Gracie says. "You get maybe an organization where the CEO of that organization wants you to do things or act a certain way, and he doesn't want to do it. Life can pretty much bully you. That's why he flips off the cameras and stuff. It's not to show disrespect for the crowd or the event, but it's basically saying to himself: ‘I'm not going to let this event be bigger than me. I'm not going to let it intimidate me.' And that's all that that means."
Diaz, brash as ever, went on the offensive by criticizing promoters and regulators while offering his endorsement of marijuana and all things organic. His suspension served, Diaz returned to the cage in September by outpointing unknown Hawaiian Mike Aina (Pictures) in Honolulu.
With Noons' domination of Edson Berto, EliteXC put together its first 160-pound title fight. "I'm very confident in my jiu-jitsu and wrestling," Noons says. "I just tend to want to stand. I like to fight. I like to fight people that like to fight, and I like to finish the fight."
If those words were meant to tempt Diaz, Noons won't have to try hard. An interesting style clash looms: Diaz of the throw-punches-like-Kobe Bryant-tosses-up-shots school, and Noons with his combinations punctuated by power shots.
"He's never fought anybody that's pushed him hard, that's tried to beat him," Diaz says of Noons, a 5-2 fighter from San Diego. "So I think I've got the upper hand when it comes to experience, especially when it comes to MMA. A lot of stand-up fighters, their experience level is varied I think."
Most anticipate the bout, shown live on Showtime at 10 p.m. ET and delayed to the rest of the country, will play out on the feet -- especially with the way Diaz has engaged foes' strengths in the past, a tactic that played a role in each of his six losses.
"I do have a grudging respect for him for that, though," says Gracie. "He's never not taken a fight. He's never complained about a fight. No matter who he's fighting, he goes in there and goes for it."
A win over Diaz, whom Noons calls No. 1 in the world after defeating Gomi, would immediately vault the underdog fighter into the discussion of a division that holds a glacier-lake deep pool of talent.
Despite the high stakes Diaz was incredulous when asked to compare the relevance of this bout versus others during his career.
"All my fights are important," he barked.
"I was meant to fight. I wasn't meant to do s--- else, that's for sure."