The former WWE superstar spent 18 months preparing for that moment. In fact, since his debut at UFC 81 in February of 2007, Lesnar has done nothing but listen to how green he is.
And how he couldn't finish Heath Herring at UFC 87 despite the perception that the "Texas Crazy Horse" has no ground game. Or how he was losing to Randy Couture at UFC 91 but scored the win because Father Time robbed "The Natural" of his reaction speed and Lesnar has giant mitts.
Leading up to his rematch with Mir, everything about Brock was how awful he was technically, how preposterous it was that a 3-1 wrestler was championship material. Mir even offered to train him after the event to help him become better.
And the fans?
Well, for starters there were the steroid allegations, because we all know that even though you've never failed a drug test in your career, you're still on steroids if you are blessed with a body that keyboard jockeys could never achieve.
Talk also surrounded the giant sword tattooed on his chest, because it is completely relevant to his UFC career. And the WWE? Scarlet letter can't even do that stigma justice.
Then Lesnar walks out to the UFC 100 main event to a chorus of boos. The same people who cheered Georges St. Pierre when he had top position on Thiago Alves booed Lesnar in that same position. Lesnar wins and they hiss at him like a villain from a silent film.
Eighteen months of abuse. Eighteen months of eating shit from most of the world gets funneled into Lesnar's bloodstream and erupts in an emotional post-fight adrenaline dump.
I believe the UFC had a tagline not too long ago ... something like "As real as it gets." Well it got real -- and now it looks like a lot of people are having a difficult time handling it.
Welcome to the new era of ultimate fighting. You've heard the old adage, "Be careful what you wish for?"
In the real world, there are heroes and there are villains. There are also some people who are a little bit of both. If you want to have a real sport with real people, then this is some of the baggage that comes with it.
Critics have slammed Lesnar's post-fight antics as phony posturing, triggered by a pro-wrestling mentality that is provoking by design.
You want phony? How about his poorly-scripted and ham-handed apology in the post-event presser that clearly reeked of Dana's paddle.
I believe that Brock going on an emotional bender after the biggest win in his life was real. Slurping down a Bud Light to soothe some wounded souls afterward, was not.
Fans who cry for sportsmanship have an argument, but my problem is those are the same fans who Mir'd him before, during and after the fight.
Don't poke the gorilla in the cage and then act surprised when he gets out and goes on rampage.
Now before you claim I'm typing this rant using Lesnar's pasty pencil, I'll warn you I'm no Lesnar nuthugger. Taking a verbal dump on the UFC's biggest sponsor was a little dumb, and I'm not sure how much interest I have in when he's going to show Mrs. Lesnar his little Gopher.
But let's keep things in perspective. At an event that saw Dan Henderson purposely strike an unconscious Michael Bisping to send a message -- I don't want to hear about Lesnar being unsportsmanlike.
And now UFC heavyweight contender Shane Carwin wants to blog about Lesnar being "lame?" Wonderful. Isn't this the same guy who hastily slammed Brock in his blog for Internet comments that Lesnar didn't even make?
What does Carwin, who's never headlined an event in his life, know about the pressures of carrying the biggest pay-per-view in UFC history?
Carwin's primary concern as of late has been which of his dimwitted fans is going to coin his goofy new nickname. I would like Carwin to spend a year being ridiculed for a pro wrestling career, accused of steroids, pressured into carrying a pay-per-view, etc. before speaking out on Brock.
Lesnar has ESPN in his barn. In four fights he's been forced to face Frank Mir (twice), Randy Couture and Heath Herring. Carwin, who is being coddled to the point of absurdity, had his biggest test to date against Gabriel Gonzaga at UFC 96.
Despite losing, "Napao" re-engineered Carwin's nose with one punch.
The UFC is a sport based on real fighting between real men. No matter how professional your standards, fighting carries a certain emotional intensity that just doesn't come with an on-off switch.
Brock Lesnar is a villain. He lassoed Heath Herring, gave no respect to Randy Couture and got in the face of a battered Frank Mir. He is the antithesis of a Rich Franklin-type of fighter, who thanks God and his opponent in his post-fight speech, then proceeds to shake hands with everyone from the opposing trainer to Mike in Accounting.
I like Franklin, just as I like Lesnar. They're real people who are different in their styles, emotions and philosophy. I appreciate the ability to root for one and jeer the other.
And to me, the genuine moments in this sport are also the most unforgettable.
From Forrest Griffin's breakdown after losing to Keith Jardine at UFC 66 to Houston Alexander screaming at a fallen "Dean of Mean" at UFC 71 to Michael Bisping's jump-for-joy reaction to beating Matt Hamill at UFC 75, those images provided me with an emotional investment in not just the fighters, but the entire sport.
Lesnar comes across as a jerk and a bully. But he also comes across as one of the most dangerous heavyweight fighters in the game today.
The more vile Lesnar gets, the more I want to see him taken out. Count this fan among the legions of MMA fanatics who will reach into their wallets for the next Lesnar pay-per-view.
And I'm not lost on the irony that a man who made his name in the land of make believe is now facing ridicule for being "as real as it gets."