For five years, Georges St-Pierre has been more than just one of the great champions in mixed martial arts history. He's been the face of a promotion – one of the cornerstones in a jaw-dropping business turnaround from epic failure to sensational success.
He exuded class, portraying himself and, by extension, his fellow MMA fighters as thoughtful, polite and dedicated athletes who wanted nothing more than to compete against the best.
For all the problems he has been forced to deal with on a daily basis, from failed drug tests to drunken binges to homophobic slurs and thoughtless tweets, UFC president Dana White never once had to worry that he'd be awakened from his sleep because St-Pierre had gotten into trouble.
St-Pierre brought hordes of positive media attention, attracted fans by the droves and generally set a standard for what a professional fighter should be. He's always been in magnificent condition and pushed the sport to new levels. He still executes moves in the cage others simply are unable to do.
Yet, it will be in many ways a very different St-Pierre who steps into the Octagon at the Bell Centre in Montreal on Saturday to defend his welterweight title against archrival Nick Diaz in the main event of UFC 158.
Diaz has managed to puncture the notion of St-Pierre as the cool, unflappable, imperturbable athlete.
Diaz's taunts and his actions – missing several news conferences that St-Pierre managed to break his training schedule to attend – have seemingly pushed the champion beyond his limits.
During a wild conference call on Thursday, St-Pierre angrily referred to Diaz as "an uneducated fool." So frustrated was he during a lengthy Diaz rant that St-Pierre, whose first language is French, said "I don't understand half of the words that you are saying because your English is bad. I speak English better than you, man."
His voice rose and his normally placid demeanor was sharp.
The UFC's feature commercial promoting the fight shows White saying St-Pierre referred to Diaz as the world's most disrespectful man.
Over the last several weeks, Georges St-Pierre has spoken of the dark place in his head so frequently, it's become an Internet meme.
Former fighter Danny "Boy" Downes, who now occasionally writes for UFC.com, created the hashtag #GSPsDarkPlace on Twitter and began a series of wisecracks that made fun of the dark place in the champion's head.
It was all in fun, but it mockingly pokes at the squeaky clean image St-Pierre has not only crafted, but carefully maintained.
For years, no matter how disrespectful or out of bounds his opponent may have gotten, St-Pierre remained cool. He formed a game plan, stuck to it religiously and racked up win after one-sided win.
It was simple, really. He never let himself get angry or distracted from the ultimate goal, which was to win the fight in the simplest manner possible. If his opponents were best on the ground, St-Pierre kept the fight on the feet. He battered the faces of wrestlers Jon Fitch and Josh Koscheck into ground chuck with his precise and powerful striking.
Against powerful strikers like Dan Hardy and Thiago Alves, St-Pierre used his uncanny takedown ability to put them on their backs, where they were essentially helpless.
"I'm the one who decides where the fight is going to go," St-Pierre said during a telephone interview with Yahoo! Sports in a rare moment of braggadocio that, notably, came prior to the Thursday conference call.
Diaz is a well-rounded fighter, but his striking and unbelievable stamina are his strengths. It would stand to reason that St-Pierre would look to take Diaz down and try to control him and pound on him from the top.
The unknown, though, is whether St-Pierre remains in control of his emotions or whether Diaz has gotten through enough to cause him to fight angry.
An angry St-Pierre could make mistakes that could open the door for an upset victory by Diaz.
St-Pierre, though, as angry as he is, insisted he'll fight the calm, controlled fight he and his staff have prepared, regardless of what Diaz may say or do.
"Do you know how many times fighters have said things and tried to get into my head?" St-Pierre said. "He can say what he wants, but that's not going to work. I know what I want to do and what I need to do and I'm going to go out there and do it."
Diaz has unquestionably gotten under his skin and on his nerves. But just as unquestionably, St-Pierre has proven time and again in his lengthy reign as UFC champion he's able to put emotion aside to fight like few men ever have.
Nothing he may ever do should surprise.
Memorable Moments on Yahoo! Sports:
Other popular content on Yahoo! Sports:
• Watch DeAndre Jordan obliterate Brandon Knight with ferocious dunk
• Sources: NFL star Tony Gonzalez will return for right price
• Infographic: Memorable moments of Big East tournament
• Hooters ball girl has nowhere to hide after humiliating mistake