That's the problem with obsession: when the thing that has consumed you ends up crumpled in a dustbin, there is desolation. And when the bitterness fades and you realise you could have done more to hang on to it, the desolation deepens.
When Scott Quigg was a boy of 15, he would spend family holidays in Florida shadow boxing in a garage. No Mickey Mouse and theme parks for him. For 12 years, Quigg yomped towards what he believed to be his destiny. It never looked like this: slumped in a dingy press room, broken jawed and beltless.
When it was suggested that he should look sadder, Quigg replied: "It's an act. No point moping about. But it's killing me inside. I'm absolutely devastated."
His promoter Eddie Hearn, downbeat as you'll ever see him, said there had been tears in the dressing room following Quigg's defeat by Carl Frampton at the Manchester Arena. Wayne Rooney had popped into the wake to offer consolation. He chose the wrong gig. Across the way, a party was in full swing.
Frampton never got the 'star' dressing room, but he managed to fit half of Northern Ireland in it anyway. Martin O'Neill, AP McCoy, a well-oiled James Nesbitt. It's almost obscene to have joy and devastation in such close proximity.
Quigg thought he had maybe been unlucky, but he wasn't too convincing. For the first half of the bout, the Bury fighter simply didn't do enough. It's all very well saying how comfortable he felt. Problem was, Frampton felt even comfier.
"I won the first six or seven rounds doing very little," said Frampton, who added Quigg's WBA super-bantamweight belt to the IBF belt he already owned.
"I don't really understand his tactics. He came on a bit at the end but in the first half of the fight he was giving me rounds.
"I remember sitting on my stool after four rounds and feeling like I hadn't done anything. And I'm not going to be daft and get involved in a fight when I'm winning rounds with my jab."
While the hype machine suggested we were in for a 12-round tear-up, both Frampton and Quigg had actually prepared for a chess match. And while some fans felt short-changed, those who appreciate boxing appreciated Frampton.
Quigg was correct in his assertion that Frampton didn't land much in the first half of the fight. But with Quigg wary of committing himself, Frampton landed enough. And somebody has to win the rounds, however quiet they are.
"Carl's feet won him the fight," said Frampton's trainer Shane McGuigan, who won his personal duel with Quigg's trainer Joe Gallagher hands down.
"Quigg's feet were terrible, as soon as he went to load up, Carl just stepped off him and caught him with two or three shots. It seemed very strange that while Quigg is apparently so fit and so strong, he gave away the first half of the fight."
It was a Frampton uppercut that broke Quigg's jaw in round four and apparently derailed his best-laid plans. But Quigg has form for starting slowly - he only just caught up with Cuba's Yoandris Salinas in 2013 - and surely Gallagher, Ring magazine's trainer of the year, must shoulder some of the blame.
Whereas just about everyone else in the arena - aside from the judge who awarded the fight to Quigg - thought the Englishman was blowing it, Gallagher thought he was watching an even fight. No wonder there was too little, too late.
"I had it level after four rounds and even though we lost the middle rounds, I couldn't believe it when someone told me TV had us 6-1 down," said Gallagher, who also trains Liverpool's fighting Smith brothers and lightweight world champion Anthony Crolla.
"Scott wasn't getting hit in those early rounds, came on strong late on and almost had Carl out on his feet in the 11th. It was a round either way or a draw."
But the reaction of Hearn was more instructive. The man who was involved in tortuous negotiations for the best part of four years in a bid to make the fight happen just looked disappointed. Frampton, Hearn said, was a deserved winner.
While the late rounds were compelling, the tactical nature of the first half of the fight makes it easier for Frampton to wriggle out of a rematch. Frampton, who had wanted to make the crowd restless, called those early rounds "boring".
That's a gift in itself, managing to turn down the voltage on 20,000 excited souls. The atmosphere beforehand made you grin. Not since Ricky Hatton fought Kostya Tszyu in the same arena in 2005 had there been such a racket.
Next on Frampton's hit list is Mexico's Leo Santa Cruz. The undefeated former super-bantamweight champion defended his WBA featherweight title against Spain's Kiko Martinez - whom Frampton outpointed in 2014 - on Saturday.
The Belfast man, who is now undefeated in 22 professional fights stretching back to 2009, says he is willing to step up for a big-money fight and his camp would be hopeful of making that match at catchweight. Both boxers have links with American boxing mogul Al Haymon, making it more likely to happen.
Quigg, too, has options. But the fight he really wants - the fight that will gnaw away at him, right into his guts and to the marrow of his bones - is a rematch with Frampton. But that's boxing: it doesn't do what you want it to. And it just keeps on gnawing, even in retirement.