During warm-ups, Brown, 36, says he just couldn't get amped up. There were no prefight nerves, even though he was fighting a dangerous, popular opponent, in the co-main event.
Then at the start of the third round, with the score tied at one frame apiece, Brown acknowledged a request from Cerrone to touch gloves and hug in the center of the cage. Moments later, Cerrone knocked Brown out cold with a head kick.
"I hate to sound like I'm making excuses, but these last few fights I've went in with no real hunger in my heart," said Brown, on ESPN's 5ive Rounds podcast. "Last fight, I remember being in the back warming up and I said to myself, 'Man, I'd rather go back to the hotel and chill. I don't even feel like being here.'
"And I guess that third round, that's what happened. I relaxed even more. A lot of people are talking about, 'He shouldn't have shook hands or gave him that hug.' I look back on it myself and say, 'I never would have done that a few years ago. I never would have hugged a guy. If a guy came up to hug me, I'd punch him in the face for it.'"
Less than three years ago, Brown (20-16) was on a seven-fight winning streak and knocking on the door of a UFC title shot. Since then, he is 2-4 and has been knocked out in his past two fights.
A lack of fire, coupled with the disappointing results of his recent fights, has convinced Brown to take an "extended break." He admits that at any moment, under the right circumstances, that plan could fly out the window, but he's having very honest, pointed conversations with himself regarding the state of his career.
"What it really comes down to in the end is I look at myself and wonder, 'Have I peaked out?'" Brown said. "Have I gotten as far as I could possibly get? I'm not going to go in to a fight just to fight and I'm not going to go in just for money.
"I've gotten up to No. 5 in the world and I've fought former titleholders. I've performed well against the best in the world. If I've peaked out, that means it's time to stop." Matt Brown
"I've gotten up to No. 5 in the world and I've fought former titleholders. I've performed well against the best in the world. If I've peaked out, that means it's time to stop."
At the moment, Brown is focusing on his role as an assistant coach to T.J. Dillashaw on "The Ultimate Fighter" reality series. The show, which is currently filming in Las Vegas, pits Dillashaw against current bantamweight champion Cody Garbrandt.
Brown is interested in a potential transition to coaching full time, even though it's not something he has much experience in. However, he believes he could bring a lot to the table as a coach, particularly in mental approach and strength and conditioning.
A professional fighter since 2005, Brown says his resume speaks for itself -- particularly in terms of cardio, strength and injury prevention. That said, even if coaching turns into a viable transition, Brown admits it will be difficult to hang up his gloves.
It's obvious he doesn't want to stop fighting, but he doesn't want to show up to an arena on fight night and lack motivation again, either.
"I don't want to be that guy," Brown said. "I think we're so narrow-minded and tunnel-visioned for so long. So enveloped in this one world, one goal, one focus -- how do you step away from that? How do you transition to something else when you don't see anything else for years and years?
"Now, all of a sudden you look around and there is this whole other world that I wouldn't even say I necessary fit in. I fit in with this small group of savages, beating each other up for money. That's where I feel like I belong. That's where I want to stay. But if it's risking my health, that's another thing."