Every athlete, no matter how successful, has one.
One game. One opponent. One missed opportunity.
For some athletes, perhaps especially the most competitive, those missed chances become their version of Ahab's white whale. They may reach the highest heights their sports have to offer, but still, that one thing will nag at them.
Doug Flutie's one thing is actually four things: the four games the Eagles played against the West Virginia Mountaineers during his career in Chestnut Hill.
Asked if there was anything about his Heisman Trophy-winning season for Boston College in 1984 that he would change today, Flutie at first said what you're supposed to say.
"I don't think so," he said in an interview. "I don't think there's anything I'd change."
And then he slipped that one thing in there.
"I'd love another shot at West Virginia," he said, "but things couldn't have played out any better. We did everything we could possibly do."
Everything, that is, except beat the Mountaineers.
He watched from the bench as the Eagles lost 38-10 to WVU in 1981, three games into his freshman season. When the Eagles struggled against Penn State in the next game, Flutie got the call and won the starting job with his play in the second half of a blowout loss. He never gave the job back.
In 1982, Flutie had perhaps his worst game as a collegiate passer when he went 9-for-33 for 122 yards, 4 interceptions and zero touchdowns against the Mountaineers. Final score: WVU 20, BC 13.
In 1983, Flutie threw the ball 51 times -- second most in his BC career (53 vs. Penn State in '84) -- completing 23 passes for 418 yards, three interceptions and one touchdown. The Eagles lost 27-7.
And in 1984, in his last shot at conquering the Mountaineers, Flutie came the closest he'd get. His final passing stat line reads: 21-for-42, 299 yards, 0 INT, 1 TD. The final score: 21-20 WVU.
Why did the Eagles struggle so badly against West Virginia?
"They'd run an eight-man front and we had trouble handling them," Flutie said. "They'd blitz their tail off. It just seemed like a lot of teams -- we could pick 'em apart. West Virginia, it was all or nothing. They'd either sack you or you'd make a big play.
"You'd make a handful of big plays a game, because they'd blitz."
But the big plays went both ways, and West Virginia always came out on top.
It's the missed chances that irk Flutie the most, even two decades later.
"I remember having two touchdowns called back for holding," he said of one game versus WVU. "Those were our opportunities, and we let them get away."
The way he talks about them, it's clear Flutie enjoyed the competitions between the Eagles and the Mountaineers. He wishes he'd come out on top, but he appreciates the struggle.
"It was never an easy thing," he said of playing WVU, "I was always getting hit while I was throwing or a guy would have to make a great catch just to get a first down."
It's just one thing -- but it's one thing that clearly is still on this competitor's mind.
Jack McCluskey is an editor for ESPN.com and a frequent contributor to ESPNBoston.com. Follow him on Twitter @jack_mccluskey.