The Pete Carroll era at USC peaked on the afternoon of Dec. 3, 2005. The top-ranked Trojans not only won their 34th consecutive game by beating archrival UCLA, they humiliated the No. 11 Bruins, 66-19. The victory clinched USC's spot in the Rose Bowl, where the Trojans would play for the national championship.
As soon as the game ended, parents, friends, celebrities and journalists engulfed the Trojans on the field at the Los Angeles Memorial Coliseum. The USC band played "Conquest." Amid the clumps of people, Carroll wandered by alone, the walking definition of delight.
"Why would you want to leave the field right now?" Carroll said. "Where would you go?"
The Trojans never reached that peak again. The first step down came with 19 seconds left in the Rose Bowl, when Texas quarterback Vince Young completed a career night (267 yards passing, 200 rushing) by scoring on a fourth-down run to win the national championship, 41-38.
Believe it or not, that's the last time USC has been No. 1 later than September. That was the last game for Matt Leinart and Reggie Bush, the Heisman twins. The dynasty, at least the national part of it, ended there.
Carroll's Trojans descended the mountain, tentatively at first. This season, they bounded downhill. USC lost four games in 2009 -- four Pacific-10 Conference games.
Carroll may have looked at the top of the mountain and realized he's not on top anymore. He may have peered into the gloaming and seen the NCAA coming, a pitchfork in one hand and pictures of the Bush family manse in the other.
Whatever the reason, Carroll decided to stop climbing, and that's what bothers me. Why would he want to leave the field now?
No one wins every year. The game won't permit it. Between NCAA recruiting limitations, player injury and coaching turnover, it's virtually impossible. Carroll, after going 6-6 in 2001, his first season at USC, embarked on an incredible seven-year run. From '02 to '08, the Trojans went 82-9 (.901), won at least a share of two national championships and nearly won a third.
In 2009, Carroll was sidelined by a talent drain (he ended up starting freshman quarterback Matt Barkley) and a brain drain (offensive coordinator Steve Sarkisian left to become head coach at Washington and took defensive coordinator Nick Holt with him). The Trojans fell to 9-4. It's part of the natural ebb and flow of college football.
But the minute that USC ebbed, Carroll flowed out the door.
His decision to go to the Seattle Seahawks goes against Carroll's fierce competitive nature. He cloaked that will to win in a cool California vibe that took years off his appearance. At times, Carroll seemed so eternally young his middle name could have been Pan.
Carroll refused to display any public negativity. At spring practice in 2006, three months after the last-minute loss to Texas, Carroll described to me in detail how he would not let the heartbreak affect his team; about how close the Trojans came despite Young's performance for the ages.
"All that?" Carroll summed up. "We're up by 12 with a few minutes left and didn't win the game, you know?"
"That's the part that would drive most people nuts," I said.
"So you're saying you can't tell if it is or not, huh?" Carroll replied.
Prior to that, negative events rarely happened. A year earlier, on the morning after USC destroyed Oklahoma 55-19 to win the 2004 BCS Championship in the Orange Bowl, Carroll said of his players and coaches, "I challenged them not to go to sleep last night until the sun came up, and I was right there with them."
Any sleepless nights at USC from here on out won't be because of celebration. At least one Pac-10 head coach thinks Carroll stepped out the back door as the NCAA posse is moving toward the front. Carroll may explain his decision to leave by saying something about new challenges. He may blast the NCAA and its cast of Inspector Javerts for dogging an innocent coach.
Either way, the mess was made on his watch, and he's leaving it for the next guy to clean up.
The aforementioned Pac-10 head coach, asked via text if USC's problems this season could be pinned on a lack of talent or experience, replied, "Young. Fell off at skill positions, though."
You never worried about Carroll's ability to restock the Trojans' shelves. Carroll once dismissed one of the annual rumors about his return to the NFL by asking why he would coach in a league in which you could have only one first-round draft choice a year. At USC, he could sign as many as he wanted.
"We want to find guys who will be No. 1 draft picks and who can handle it academically and socially," he once told me.
Carroll has developed 14 first-rounders in his nine seasons of coaching the Trojans, with more to come on the current roster. USC remained a cool place for blue-chippers to play. Carroll attached USC to the celebrity culture in Los Angeles so securely that the Trojans sideline needed velvet ropes.
Rappers, TV stars, film stars -- if you saw them on "ET," you'd see them at the Coliseum. USC grad Will Ferrell would show up at practice, dressed as a superhero, and give a mock pep talk. Soul legend Bill Withers would come to a meeting and sing "Lean on Me." Carroll brought that to his team without a loss of discipline or focus. I can't think of another coach who would agree to any of that.
The aura that USC cast over the Pac-10 has gone. Oregon won the Pac-10 this season by two games. The Ducks humiliated the Trojans. So did Stanford. When it came time to dig deeper, to start the climb up the mountain again, Carroll headed out the door.
Ivan Maisel is a senior writer for ESPN.com and hosts the ESPNU College Football podcast. Send your questions and comments to Ivan at Ivan.Maisel@ESPN3.com.