The public wants Brock Lesnar to be great, the UFC wants Brock Lesnar to be great, but if Alistair Overeem gets the better of him, it's going to be clear that one of the most recognizable faces in the UFC is nothing more than a fad.
Just as the Kimbo Slice hype went away in an instant, Lesnar's has the potential to do the same.
That isn't to say that Lesnar's experience in the UFC is anything like Slice's. Lesnar has shown that he has the potential to be the best heavyweight in the world when he's healthy.
He has knockout power, unparalleled wrestling prowess in the division and uncanny quickness for his size.
All of that being said, he can't afford another loss. The UFC isn't going to wait for Lesnar to get back to his "baddest man on the planet" state. He's got a limited amount of opportunities to prove he's still something special and a loss against Overeem would make his uphill battle to the top even steeper.
Lesnar isn't the type of fighter who is going to accept being defeated over and over again, a la Tito Ortiz.
He's not interested in public opinion or what the experts think. He's completely confident in his skills, but another loss would force him to take a giant leap backwards.
He steps into the octagon with the power to dictate how his UFC career will pan out. He's technically the underdog and expected to continue his demise, but it's impossible to sleep on Lesnar, who has all the talent in the world and now literally has to fight his way out of a corner.