"I always think that had I ever played for him, on one of his teams, because he was coaching when I was playing, or was on his staff, once I got into coaching, I bet we would have been, like, really good friends," Harbaugh [said earlier this week.](https://www.youtube.com/watch?v=2raQl2Fbdb8) "I learned a lot from him, just watching him, but he's just always been on the other side.
"When I was a player, he was a defensive coordinator or head coach somewhere. And then when I was coaching, we were just trying to gouge each other's eyes out…in the competitive spirit of that."
Harbaugh's Cheshire cat grin said more. Much more.
In the late 1980s and early 1990s, Harbaugh, as a quarterback for the Bears and Colts, seven times went up against Carroll, who, in that time frame, worked as a defensive backs coach for the Vikings and was later the Jets defensive coordinator and head coach before becoming the Patriots coach. Harbaugh started four of those games and Carroll's teams won three of them. In fact, Carroll the head coach was 3-0 against Harbaugh the quarterback.
Flash forward to the Los Angeles Memorial Coliseum on Oct. 6, 2007.
USC, which had won consecutive national championships in 2003 and 2004 and was a first down away from a three-peat under Carroll while birthing a trio of Heisman winners in Carson Palmer, Matt Leinart and Reggie Bush, was a 41-point favorite over Stanford.
Harbaugh, who had just been hired at Stanford when he stirred the pot by saying he heard Carroll would only be with the Trojans for one more year, led the Cardinal to a last-minute 24-23 victory over No. 2-ranked USC to end its 35-game home winning streak.
Two years later, and on the same field, Harbaugh's Cardinal waxed Carroll's Trojans, 55-21, leading to the [tense exchange at midfield](https://www.youtube.com/watch?v=WeS3VeluAmg).
"How are you feeling?" the usually unflappable Carroll asked. "Are you all right?"
The ultra-intense Harbaugh, who had just mocked the Trojans for "running in" off the field before the clock struck zero, seemed confused.
"Yeah, I'm great," Harbaugh answered. "What's your deal?"
It was a viral moment before viral moments were described as such, a meme before memes were known.
Carroll was in the NFL with the Seahawks the next year, and Harbaugh followed him to the NFC West with the 49ers, yup, one year later.
Twice a year they faced off from 2011-2014, the two splitting eight regular season meetings. But Carroll's Seahawks won the big one, that epic NFC title game, en route to a Super Bowl XLVIII victory.