THIS moment is a national treasure.

It is lodged in the memory banks of a generation. It is played out in minds and on televisions with a repetition that never induces a hint of weariness.

It is March 17, 1990, Tony Stanger, a 21-year-old bank clerk from Hawick raises his arms high above his head, grabs an oval ball and bangs it into the Murrayfield turf. Scotland consequently win the grand slam, defeating England 13-7.

Yet Stanger does not remember it, at least as a personal moment. "I have not internal memory of it,'' he says. ''I can place it my brain from outside in that I have watched it on television since many times but I have no memory in the sense that I recall the moment, or the feel of the ball or anything."

This takes national collective consciousness to an extreme level. Stanger thus shares the memory of one of the greatest moments in Scottish sport with the rest of us. As an outsider.

Twenty-five years on Stanger is now talent manager at the sportscotland institute of sport. His moment in the watery Murrayfield sun may have not been captured by his brain but it informs his every move to make the nation better at sport, to help produce the moments that not only illuminate sport but make the chasing of ball or the running against the clock a part of invigorating a nation and inspiring a population.

Stanger's precise recollections of 1990 testify to fear, apprehension and pain. The lessons from his rugby career, though, now inform the development of Scottish sport.

Stanger's reminiscence of the 1990 campaign focuses on his concern at the possibility of missing the England match. He had played poorly in the previous match against Wales. "I missed a tackle badly and if you are a winger then everyone tends to remember that," he says.

"I remember reading that the only selection doubt for the Grand slam decider would be whether Tony Stanger will play."

He was further handicapped by injury. "I decided to play the week before the England game for Hawick against Stew-Melville because I had not played well against Wales. I was caught on the ground, someone fell on me and my collarbone shifted."

Stanger thus struggled the week before the Grand Slam decider and trained with the forwards as a final test on the Thursday. "It seemed to be all rucking and tackling. I woke up on the Friday morning in absolute agony. But by the Saturday it seemed okay and I wasn't aware of it at all during the match. Adrenalin, maybe. But I did not play for three weeks afterwards."

The match against a fine England side has taken on a political, even national resonance with the backdrop of the poll tax. This seemed more than just a rugby match. Scotland approached Murrayfield on the back of victories in Ireland (10-13), at Murrayfield over France (21-0) and in Cardiff (9-13).

England, though, were heavy favourites but also burdened by the tag of being Maggie Thatcher's works team. There may not have been insurrection in the air but there was a strong disaffection.

But Stanger says: "I never got any of that. I spent the build-up worrying about whether I would be playing. That aspect of politics or whatever passed me by. It was about playing a game of rugby. That may have been naive but it was how it was for me."

Now, 25 years on, he looks back on his career for lessons. They come in a torrent.

"The challenge of my job is to make athletes world class. It is like an iceberg. The tip is about top performance but what lies below the water is the mass of hopefuls who can rise to the top," he says.

"We challenge sporting bodies to do their best." Stanger is constitutionally set up to do better both personally and professionally.

He concentrates on getting parents involved, consulting with coaches and, crucially, trying to make sure children stay involved in sport."We are now going into schools,'' he says of the mission to improve the depth and calibre of Scottish sport.

"We are a small country so we have to be as good as we possibly can be. We can not rely on a force of numbers pushing people through. And we can not have people coming through with fundamental weaknesses, looking to sort them out at 18 or 19."

His passion is informed by life lessons. He notes three essentials to the production of an athlete: physical suitability, understanding the development process, and creating the growth mindset.

"I had the physical shape. I was strong and fast," he says. "I could run round people or through them. So I had that basic, through genetics and helped by having brothers who I ran and wrestled with in a big garden."

The growth mindset was partly acquired, partly inherent.

"I look at my time in rugby and I saw even then there was a lot of stuff that did not make sense. Why are we training for an aerobic sport when we are playing an anaerobic sport? I had other questions. I went back to university at 25 to study sports science and come up with some of the answers."

He adds: "I am very shy, introverted but I think deeply about things. I always wonder: 'Why?"

This means he is constantly evaluating his role. He knows how difficult it can be to keep kids playing sport, knows that parents have a tough job in communicating with their children in victory and in defeat. He accepts there can be setbacks, but has no doubt about ultimate success.

"Can we continue to produce world-class athletes? Is there someone out there who will score a Grand Slam-winning try for Scotland. Absolutely. There are more of those people about that some may think they are."

One of them was, and is, Tony Stanger. "I was within a whisker of giving up the game,' he says. "When I was 15 or 16 I looked around me and thought: 'There is no way I am going to play for Hawick'. I thought there were hundreds of boys better than me."

However, a poor experience can be a good lesson. The growth mindset kicked in and Stanger progressed up the ranks, eventually winning 52 caps for Scotland and playing for the British Lions.

He was never quite satisfied, however. "I could see why I was successful but I could see I could be better," he says.

"I have absolutely no regrets about my playing career. My experiences have led me to where I am today. But there is no doubt that I could improve that player of 25 years ago with the knowledge I have today."

These lessons were conducted on rugby pitches, in lecture halls and in rooms at night, studying the theories and the figures that can build sporting success.

But if these readings and experiences are lodged firmly in the brain it is curious that the defining moment of 1990, the most astounding passage of a highly successful career, remains elusive for Stanger, perhaps permanently beyond capture.

"Yeah, it is strange but maybe it's because it was an instinctive thing...a run, a grab and a grounding. I tend to remember things that I had to work on and then turned out well."

Like what? He says: "Well, one of my best memories in rugby is playing on tour in New Zealand at centre and giving a slick exact pass to Derek Stark."

This testifies to the Stanger doctrine. Months of work and practice had produced a satisfactory result. He had his moment.

The rest of us will have to console ourselves with the dive in the corner in 1990 that sent Will Carling and his mates homewards, to think again.