It was when Ben Turner, one of the directors who helped make The Class of '92, told Ryan Giggs that he is a Sunderland fan that he realised what made Manchester United great. "Most people laugh at me," Turner says. But not Giggs. United's new manager was having a flashback to something terrible instead.

"He looked at us, no joke, and went: 'I seem to remember you beating us in 1997,'" says Turner, who directed the film alongside his brother, Gabe. "He remembered the one time we'd beaten them. That stuck in his mind. It was very much that sense of when you're on the beach, you think about the trophy you didn't win and, when you win it, you celebrate and move on. We were talking about the game. John Mullin scored the winning goal. I don't think he ever did anything else in a Sunderland shirt. But Giggs remembered the time he'd lost to us."

For Giggs, and the other members of that generation – Nicky Butt, David Beckham, the Neville brothers and Paul Scholes – losing was not an option. The film explores how these six boys came to dominate English football, and that conversation about a defeat in 1997 hammered home to Turner that it was an insatiable desire for victory that set them apart. It is why United turned to the class of '92 until the end of the season after David Moyes was sacked. Giggs and his assistants, Butt, Phil Neville and Scholes, have the club in their blood.

"We spoke to Giggs, to congratulate him, and he said he didn't bat an eyelid when he was asked if he wanted the job," Turner says. "He'd accepted it before they'd even finished asking him. They buy into the story of Manchester United."

Turner is not surprised that Giggs, the leader of the pack, is now the manager. "If they were ever going to do it there was an unsaid feeling that he is the leader of the group, but they all wanted to be involved at United," he says. "I mean, they managed to talk Scholes out of retirement and he's back now. He answered the call so quickly. But it's not a surprise that Giggs would be the manager.

"They all have a lot of respect for him because he broke through first and he was the gold standard for them. I think they all look up to him."

Turner believes that success has not changed them as people. "They are very down-to-earth," he says.

There is an aura to them, but also a sense of camaraderie – normal people whose childhood dream came true. "They were like any group of old mates who'd been on an amazing adventure together. But they're very affectionate towards each other. They're very protective of each other and have a lot of respect. It seemed like a really balanced group of people, without any regrets. I don't know if they see each other all the time now, but they were very familiar instantly."

Turner admits he was worried about Scholes being too shy for the camera – fears that were soon allayed – while he remains hugely impressed with Butt. "He was great," he says. "People don't know him as much as the others, but he was one of the leaders when they were coming through and sort of looked after them. The leadership qualities and the status he has was a nice surprise."

A walk around Old Trafford brought home to Turner that he was in the company of living legends. "It was very soon after they'd all kind of retired. There's a part of the museum at the ground about the class of '92 and I felt it was like watching them pass into mythology.

"I was looking at the statue of Best, Law and Charlton as they were walking past it, and their achievements have eclipsed what those guys did. They're as big a legend as you can possibly be at that club. And as time goes by, their mythology will grow because when you don't see them play every week, the story grows."

An extended version of The Class Of '92 will be released on Blu-ray in early June