“You have to feel, this is their year. Is this their moment? Beckham into Sheringham … and Solskjaer has won it! Manchester United have reached the Promised Land! Ole Solskjaer! The two substitutes have scored the two goals in stoppage time, and the Treble looms large.”

Bodies, noise and flares … haunted other bodies, frozen … Tarnat and Scholl, still against the posts, bent double. Solskjaer off, then on his knees, the players in a huddle, the bench on the way, Schmeichel cartwheeling. Butt, pissing himself with manic, giggling laughter, Solskjaer, eyes closed, now fully in the moment. Tarnat still on the post, Gary Neville collapsed on the ground, Kuffour beating the ground. Cut to Lothar. Scholl slumped against a post, Kahn on the ground, Collina trying to pick Kuffour up and failing, others staggering about as though hit by a lorry, Scholl suddenly inspired and racing to kick off, Effenberg still flat on his back, patted on the chest by Collina, Kuffour ranting at himself, Kuffour stomping.

In the seconds immediately following the goal, the calmest man in the ground was Solskjaer, pausing to fill his cheeks and exhale before setting off apparently unflustered, arms wide, fingers pointing and mouth clenched closed – like a man agreeing with himself, and definitively so. Like a man who knew.

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“I have a feeling, sometimes, when I think it’s gonna be my night, I think I’m gonna score,” he said afterwards, “so I called one of my friends back in Norway. And I told the reserve team coach as well, ‘I think this is gonna be my night’ just before the game started.”

And no one deserved the moment more, his dedication and enthusiasm outstanding even in exulted company – in a team full of characters befitting the cliche “he just loves playing football”, he just loved playing football.

Quite simply, Solskjaer is a mensch; someone you’d be proud to call a friend, rather than a public personality with an admirable trait or two. Liked by everyone, including Roy Keane, his radiant huggability is not a front; very clearly, he just gets life, ensconced in his own skin to an extent that is almost moving, an equanimity that joined him on the pitch.

He was also the only player to speak out against the Glazers – and guess what! It didn’t cost him his job! Or anything else! But even before then, even before this, his was a special status. United’s following is as cynical as exists in world sport, on first name terms with very few men: Sir Matt, Duncan, Denis, George, Eric, Ruud – and Ole. It’s true that the nature of the names helps, but nowhere near as much as the nature of their owners.

And of course, despite supplying the historic Treble-winning goal in the most dramatic end to a football match that there has ever been, he retained the same serenity. He knew that the goal, though it earned him a boot deal, “never made me a better player – made me a bigger name, maybe”. So his focus afterwards was the same as before: “To improve to make sure that I play more than 15 minutes next time.” In the 14 years since 1999, he’s watched a chunk of the game just once – the period for which he was on the pitch – when he got back to Norway, to oblige his dad, who’d not been able to make the game due to work commitments, with only a short while spare prior to setting off again. And even though, for much of his career, he was in and out of the starting 11, the only time he queried the manager’s decision was when Yorke was picked ahead of him, despite being effectively retired from serious football.

That same evenness manifested the following season when, after injuring Sami Hyppia with a studs-up tackle, he first scored while Hyppia was off the pitch receiving treatment, then went into the Liverpool changing room at half-time to apologise. Not exactly the ethos of Hughes, Whiteside and Robson, but with a charm, if not an attraction of its own.

But, of course, he is still relentless. Interviewed after Molde’s first title, he refused to dwell on the achievement, instead talking about ex-United players who’d succeeded in their first season of management and failed subsequently, already plotting how to avoid that happening to him.

This attribute was also in evidence in his comeback from injury at the start of 2006–07, after effectively three seasons out, another example of that shared abnormal devotion to the game. Giggs is still playing at 39 and Beckham retired at 38; Cole stopped at 37, Irwin 38 and Schmeichel 40; and even those who, on the face of it, might have been expected to finish early, Yorke and Sheringham, were at it until 38 and 42 respectively. And then there’s Scholes, who first returned from a serious eye injury, then returned from retirement. Once asked to complete the sentence “I love football because …” he could respond only with “because I just love playing football”.

In There’s Only One United, Geoffrey Green quotes a piece from the Manchester Guardian, written in 1934: “Sometimes he does daredevil things that make the directors feel old before their time. But who would have him different? He laughs equally at his blunders and his triumphs, which of course is the privilege as well as the proof of a great player. He would be a certain choice for that select 11 of Footballers Who Obviously Love Football – and that is the highest praise of all.” The man it’s describing? Matt Busby.

Losing his father and three uncles as a young boy during the first world war, serving in the second, and then losing so many of his players at Munich, Busby understood precisely the role of football as pleasure and treasure. And the Treble-winning squad understood something of this too, an unusual combination of characters, many of whom had been forced to contend with the horror of not making it.

Schmeichel and Stam both spent time in the army, Schmeichel not turning professional until he was 24, while Stam didn’t play in the Eredivisie until he was 23. Irwin was given a free transfer by Leeds; Keane learnt that he was too small, writing to, and unwanted by, every top division English club, only signing for semi-professional Cobh Ramblers at the age of 18, before suffering a career-threatening injury as he reached his peak. Cole was released by Arsenal, rejected by Fulham, then ridiculed by the media and the England manager; Sheringham didn’t play in the top division until he was 26 and Europe until he was 31. Before signing for United, Solskjaer was turned down by Hamburg, Cagliari, Manchester City and Everton, while Yorke, born in a non-footballing country, sold land crabs to tourists to pay for boots, saw the game as a “way out” of his overcrowded home and slept with a football in his bed until he was 25. They played like they could not believe their good fortune.

Even among the homegrown players, there was a mental toughness and an appreciation. The Neville brothers, dubbed the Nervous Brothers by Scholes, doubted themselves and devoted their lives accordingly, and though Giggs and Beckham were always going to make it, both suffered formative and exceptional adversity; not just the most fortunate natural talents of their generation, but also the most determined.

Younger men than would usually appear in such a successful team, in strictly football terms they were adults, used to performing under pressure and practised in rebounding from thrashings and disappointments. And they experienced all these things together, developing as individuals within a co-operative, ticking off rites of passage: away trips with the first team, first-team debut, first-team squad, appearances on the bench, and then shared pride as each became a staple.

Nor were they shy of men from whom to learn; serious, focused winners like Hughes and Robson. Robson would indoctrinate them weekly regarding what it meant to be a United player, and, most particularly, that whenever any one of them were threatened, they must all be on the scene to intervene and avenge. Also influential was Cantona, and not just because he was an exponent of the peculiar European art of practice. “A lot of the flair you see in the team today is down to him,” Schmeichel observed prior to the final league game. “The young players used to look at him and say, ‘I wasn’t taught that in soccer school or in the FA curriculum.’”

“It’s a Manchester United legacy,” says Gary Neville, “that this is a club that can be the biggest football club in the world, yet can bring through young players. There’s no excuse for any other club not to follow this. The best teams that have ever been produced, produce their own players more often than not, because they have that ingrained loyalty and desire to play for that club, to do everything that matters, no matter what it takes, and that is Manchester United’s legacy, it’s not the class of ‘92’s legacy, it’s the manager, it’s Sir Alex Ferguson, it’s Sir Matt Busby, we’re just players that have come through it because they have had the courage to actually implement that system.”

In October of the previous season, United beat Barnsley 7–0. But what gave Neville the most pleasure was the composition of the team: a back four including him, his brother and John Curtis, and a midfield of Beckham, Butt, Scholes and Giggs, with Ronnie Wallwork on the subs’ bench.

“Everything we did, we were together,” recalls Butt. “We trained together, we got changed together, we ate together. Obviously Eric and the coaches there made us know that we’re all in it together, it’s not an individual thing, because we’d never have got anywhere without our team-mates.”

And this transmitted to the terraces, supporters first investing in their potential before harvesting the kinetic. The buzz of their buzz was special enough, but it was more personal than that, their experiences so easily relatable. Playing in a team of mates as opposed to a team of other people is a decision that bothers most Sunday league types at one time or another, and here they were, having their red velvet cake and guzzling it. But more generally, the empathy, connection and experience shared with them by virtue of loving United, of United being an intrinsic part of life and memory, something inculcated from an early age and always there, is a special thing. And more generally still, the empathy, connection and experience shared with them, in simply the being of friends.

Just after Scholes announced his second retirement, he was interviewed by Gary Neville, who asked what motivated his comeback. “I decided,” he said. “Well, I spoke to you and your Phil.” And their bond is evident whenever they appear together. Giggs is meant to have a dry sense of humour, but in hundreds of “just use my experience” interviews, it has emerged only once – when talking to Neville following the 2013 title win. His ability to reveal them and get them to reveal themselves is far removed from the top man, great friend of the show knee-slapping, phony couch-cliche, rather the warmth that comes with being part of something real.

“They form the core of the team, on and off the field,” wrote Keane in his autobiography, before adding with typical morbidity, “and are bonded in a way that excludes the rest of us.” But crucially, he knew this was to the benefit of everyone. “At the heart of our club there is something solid, something real, something identifiably Mancunian, an attitude created by the Six Amigos, that is fundamental to the team and its success. When players join United, however much they cost, wherever they come from, it is this attitude they must plug into.”

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Stam, though, felt slightly differently, categorising his team-mates not as friends, but “good colleagues”. He struggled to get their jokes as quickly as they made them, and though everyone was friendly, found being on the periphery less to his taste than being part of the main group, as he was when playing for Holland. “Sometimes you just miss the amateurism of football. Sitting in the canteen, drinking a beer, talking about this and that,” he said. “But that’s not here.”

Off the pitch, perhaps not – but the magical on-pitch camaraderie that swept them across Europe was exactly here, and included the entire squad. “The atmosphere and the team spirit is fantastic, and without that we could never have come to this point,” Schmeichel told MUTV, interviewed by the pool in Sitges, just outside Barcelona. “If you have knackling and all this in the dressing room, I don’t think you’ll ever get results. Our atmosphere and team spirit is fantastic, and that’s why we get results.”

The feeling and philosophy was of a family; if someone needed telling, then they were told, not gratuitously, but because it was important. And though, inevitably, not everyone liked everyone else, they all recognised that they were bound to and reliant upon one another, all working together for the greater good. Easy to say.

Making it possible was, of course, the genius of the manager, constantly on to his players about what it meant to be a team. “It was the upbringing he had in Glasgow,” wrote Neville, “that sense that you all work bloody hard together but that you stick together through that.”

So it was that when individual players found themselves in trouble, anger was directed more towards those who had allowed it to happen than the character in question; when Keane was arrested in Cup final week, it was the squad who got the going over. “Why didn’t you ring me?” asked Fergie. “Why didn’t you tell me this was happening? You’ve all gone home and got into your beds and left one of your team-mates on his own! Why didn’t any of you think to tell me?”

Similarly, when Fergie announced his retirement, the media was naturally eager to know how he’d communicated the message to the players – but in the first instance, found nobody prepared to enlighten them, the detail that did emerge later an abridged version. “It’s obviously a personal moment between us and the squad and the manager,” said Rio Ferdinand. Obviously.

And though plenty of things leaked because they always do, plenty didn’t. David James recalls his experience of the culture through time spent away with England, and how the United players would police themselves, supporting one another to the fullest extent. “All those hours of sitting around … and not once did any United player ever reveal anything to me about their team-mates, their dressing room or their manager. In an industry renowned for its gossip I find that extraordinary … Even when the media reported chaos in the United dressing room … there were no comments from the United boys. There were plenty of questions, of course. But their answers were only ever vague, or meaningless. It all contributed to that sense of separation: there were United players, and then there was the rest of us.”

And this, all of this, manifested on the pitch: outrageous perseverance, individual brilliance, collective brilliance, improbable comebacks, late goals, and intimidating unity. That’s how the Treble happened.

• This is an extract from The Promised Land: Manchester United’s Historic Treble by Daniel Harris, which is published by Arena Sport