“I am at a house fire,” Chris Lock tells Sky Sports. “I have a crew of four on my fire engine. There is a fire downstairs, a person upstairs at the window, someone screaming inside the property who I can’t see, and I have to think of the safety of my crew as well.”

He uses this example to illustrate the demands placed on him during his 19 years as a firefighter. “You are constantly dealing with people on the worst day of their lives. I still feel pressure, of course I do. And I don’t want to belittle football. But it is still a game.”

And it is a game full of fascinating characters. But a conversation with Lock, Charlton’s U21 boss, who is also working with the most talented youngsters in the country with England’s age-group teams, is not like a conversation with your average coach.

When he says “tough decisions have never been daunting to me” you can appreciate why. “The fire service has served me well,” he says. “It prepared me to make difficult decisions and deal with the consequences. As a manager, you do that every day.”

Lock’s route back to football is a curious one, because he was once a serious prospect. After working his way up through Crystal Palace, he earned a professional contract with Fulham. “I was quick and inquisitive about the game. I always wanted to know why.”

He has fond memories of Fulham, of little details picked up from Paul Nevin, Steve Kean, Jean Tigana and Christian Damiano. “I started to get interested in the idea of coaching. I was maybe too opinionated at the time,” he laughs. “The exuberance of youth.”

But he drifted from the game, a career in football fizzling away before it had really begun due to a pelvic injury. “It was within touching distance. It always felt like unfinished business,” he explains. Later, life would get in the way of pursuing the dream too.

“If I had kept playing, I probably did have the quality to get back in. But it got to the point where my partner was pregnant and you have to start earning a living. There was the football dream and the reality of becoming a father, having to provide for someone.”

Lock’s uncle, Nathan, was working as a firefighter at the time. “He put the idea into my head. I did not want to work in an office and sit behind a desk.” And what had felt like a “tough decision” at the time turned into a form of salvation. Football by another name.

“It was literally like a changing room. It was a team with older guys – the senior pros – and then younger guys, the rookies in the squad. Then, there was the watch manager. Instead of going out to play, you were going out to an emergency. That is how I framed it.”

His return to the game was a happy accident in a way, even if there was something deep in the locker that he knew he had to explore. His young sons started playing and they were both good. “It was only then, really, that I had the impetus to go back to football.”

His children were at Peckham Town. “One day, their coach left. The chairman asked if I would do it.” Eventually, the itch that needed scratching – “that was needling me in the gut” – morphed into Lock starting his own grassroots football club, Carpe Diem FC.

“I was going to do one team but it soon became three.” That was back in 2015 and with the help of colleagues it is still going now. “The idea was always to give kids of whatever ability the opportunity to play football,” he says. “It is about development not elitism.”

Even so, Lock proved good at developing elite players. Reuell Walters went on to play for England at age-group level, but there are many more success stories. His own son Paris is now with Lock at Charlton. “I am much tougher on him than anyone else,” he insists.

For a brief period, Lock found himself doing shifts with fire service in London, helping run Carpe Diem, working for Charlton and going away with England. “Family holidays weren’t in existence because I didn’t have any leave left come the end of the year.”

With his football commitments increasing beyond recognition, he called time on his firefighting career. A steady income, gone. “I put all my eggs in one basket.” Back in the crazy world of football, chasing the dream again but as a coach now rather than as a player.

As it stands, he is being vindicated. Late last year, he was part of the England coaching setup at the U17 World Cup. He has already worked with Liverpool’s Rio Ngumoha and Arsenal’s Max Dowman, two of the breakout stars of this season’s Premier League.

“They are in that bracket of player where it probably does not matter who coaches them. Whether the coach is good or bad, they will come through. But it has helped me to recognise what elite looks like and I can push the Charlton lads in that direction.”

And they have helped him get better too. “Players like that, they are not going to take waffle. They will recognise it if someone does not have the coaching detail they need. But I have always been good at building rapport. It is about fairness, integrity, respect.”

Lessons Lock has learned from a life inside – and outside – football. He is eager to credit colleagues at Charlton such as Steve Avory, Tom Pell and Rhys Williams. Others such as Anthony Ferguson, Keith Boanas and Warren Hackett have helped him with his badges.

He talks of conversations with Chris Ramsey, Kevin Nolan, Lee Carsley, John McDermott and Tim Dittmer, while his time assisting Michael Appleton with Charlton’s first team helped convince him that he could be a manager. “It kind of got my juices flowing.”

But for all the contacts, for all the commitment to coaching, if there is one aspect of Lock’s journey that captures the imagination, it is what makes him unique. “The fire services,” he says. “That is always my anchor.” It might also be why he will succeed.