What happens when a 20-year career as a professional is boiled down and reduced to one game, one moment, one goal, one strike of the boot?
Because, despite all he did in the game of football, Gary MacKay is mainly remembered for one incident, when he scored a goal on his debut for Scotland against Bulgaria 11 years ago.
That goal was a pivotal moment in Irish football history, as it meant that the Scots defeated Bulgaria 1-0 in Sofia, thus allowing the Republic of Ireland -- who had already played all their games in the qualifying group -- to progress to the finals of the 1988 European Championships, the first and last occasion when an Ireland team topped a qualifying group.
Yet that's not something that bothers MacKay, now aged 44 and working as a players' agent in Scotland. Better to be remembered for one minor moment that not at all -- and he knows he came close to being forgotten.
"People still talk about my goal and I know it will always be remembered in Ireland, but it was almost forgotten about," says MacKay, who has just published his life story, Maroon Heart.
"After I'd scored, Brian McClair had a great chance to score and make it 2-0. Now, Brian was a big name and a big hero at the time, he'd played for Celtic and was at Manchester United then. He was a much bigger name than me, I was only an unknown kid from Hearts who was making his debut.
"If Brian had scored, all the talk would have been about him, no-one would have remembered who scored the first goal, and we wouldn't be having this conversation today -- you would be interviewing Choccy instead," Mackay told the Herald.
"So it's nice that I still have the goal on my CV as I know what it meant to Irish football.
"The reason the interest in that goal is still around is because Irish and Scottish football is still at a low ebb. It's a while since either the Republic or the Scots qualified for a major finals; it might be another few years before either of us qualify again, so people like the nostalgia factor surrounding that goal.
"It was a great moment for Irish football in Sofia that night as my goal allowed Ireland to qualify, but it was a pretty good night for Scottish football as well.
"Scotland were used to qualifying for major championships, but that's not the case now, so I think it's nice for people in Ireland and Scotland to comfort themselves by looking back to moments like that win in Bulgaria."
The game in Sofia was a shock for all. Bulgaria, then leading the group and favourites to qualify for Euro 88, had not lost a qualifier at home in five years. The Scots had not won away in the group and had a dismal away record -- in the previous away match they'd lost 4-1 in Belgium, while three weeks after the win in Sofia, Scotland wrapped up business in Group 7 of the qualifiers with a 0-0 draw in Luxembourg, the first point gained by Luxembourg in the group.
"I think we were all in shock, because no-one expected us to win and certainly no one expected me to score the winner," says MacKay.
"That was my international debut; it was my first and last goal for Scotland. I had come on as sub for Paul McStay and I was just delighted to get on the field and get my debut, so to score was beyond my wildest dreams.
"A player from Hearts hadn't scored for Scotland since the 1958 World Cup finals when Jimmy Murray scored, so for a club seen as the third club in Scotland to wait 30 years for a goal and then get such an important one was amazing, it was a massive thing for me."
It's hard to quantify the impact that the goal and the win in Bulgaria had back in Ireland. The Bulgaria-Scotland game was shown live on RTE TV, but it seemed like a half-hearted affair; no-one really expecting the unthinkable to happen.
The previous day, Ireland had beaten Israel 5-0 in a friendly at Dalymount Park, and the talk was more of the future and a young hat-trick hero called David Kelly than any real ambitions of making it to West Germany.
But then MacKay's goal happened and the rest is history. There were no mobile phones, no SMS updates, no live broadcasts on Sky Sports News to allow the Scots to realise what was happening in Ireland, and the first indication MacKay had was when Packie Bonner was there at Glasgow airport to welcome home the Scots and MacKay in particular.
"Packie was there at the airport with a bottle of champagne when we landed. I'm sure he had the receipt with him and got me to pay for it," jokes Mackay.
"The response when I got back was phenomenal. I got so many letters, thank-you cards and invitations to come to Ireland that I couldn't keep track of them all."
Yet Mackay eschewed the offers and the chance to milk it on the back of Irish gratitude -- as Ireland prepared for what was in store in the summer of 1988 in Stuttgart, Hannover and Gelsenkirchen, he was back to the bread and butter of making it with his club, Hearts, and establishing himself in the Scotland team.
"I had a career to think of, so I didn't head off on a tour of Ireland for a few months, tempting as that might have been," he says.
"I have visited Ireland many times since then and people have always been grateful to me.
"The last time this came to me was last year. I played in a charity match in Southampton, when teams of old pros from England and Scotland played.
"Jim Beglin, who I had never met before, came up to me there and he came onto the pitch, shook my hand and thanked me for something that had happened 21 years earlier, and that meant a lot to me," he adds.
Looking back now, it's amazing to think that it still happened at all. The Bulgarians had a full house of 60,000 fans in Sofia that night, the pitch was poor, not the easiest of circumstances for a demoralised Scotland side.
"Don't forget that this was a very good Bulgarian side -- they had beaten Ireland in Sofia a few months earlier," says MacKay.
"They had people like Stoichkov in the side and they were a very good team, a real quality outfit, so it was a sensational win.
"I don't think anyone expected us to win. Even Jack Charlton didn't think it would happen. From what I remember he was out golfing that day and didn't even see the game.
"Jack didn't hold out much hope; neither did the Scottish media or the fans, so I suppose that our win there, in front of 60,000 fans on a sticky pitch, shows that anything can happen in football and it's the kind of thing that restores your faith in the game."
In terms of making headlines, that was about as good as it got for Mackay. He had a decent career in Scotland, playing for Hearts (1980-1996) and holds the club record for appearances there as well as a spell with Airdrie (1996-1999) but managed just four senior caps and never scored for Scotland again.
"I never hit the heights after that, I know that," says MacKay. "But I went on to play professionally for 17 years with Hearts and another bit with Airdrie.
"So I don't regret the lack of major success. I am grateful that I played professional football for 20 years, I played for my country.
"I won nothing with Hearts and I never played in a major finals with Scotland, but I still have things to be proud of.
"I was dealt some good cards as well as the disappointments."
When he finished playing, MacKay had a brief spell as manager with Airdrie but it was not a happy one, as the club went into administration and he soon turned his back on the club game, instead qualifying as an agent,
That's his current gig (since 2000) and he has high hopes for some of the young Scottish players on his books, like Inverness lad Ian Black and Under-21 cap Ian Wallace, while he also does work for Talksport radio and helps out as a matchday ambassador for Hearts.
MacKay still gets the occasional card or handshake from an Irish fan, grateful for that goal which gave Ireland the lift the nation needed in 1987.
"It will probably never go away and I won't complain about that," he says. "Being honest, I would of course prefer if the goal meant that Scotland, not Ireland, went to the finals in Germany, as I never got to play in a major tournament.
"But Ireland managed to go, I played a small part and I will have that with me always."