IT is all about the moments. The tiny things that matter so much. Get them right and you can achieve anything; get them wrong and you will never let yourself forget it. It is sport, it is brutal.

So though there is nothing more exciting for a player like Scott Hastings than taking part in a Rugby World Cup, he also understands one basic fact — there are 620 players about to launch themselves on the hunt for global glory and 590 of them will head home with their heads crammed with disappointment. Only one squad will have no regrets, no slips, no “what if” moments.

So it is that for all the great times he has experienced, all the victories, all the glory moments Hastings has enjoyed in a career as a player and pundit that goes all the way back to the inaugural tournament in 1987, it is the disappointments that dominate. It does not dampen the exhilaration or anticipation one iota.

“My experience playing for Scotland is that everything is magnified, everything is very focussed. It is just a wonderful opportunity because you are on a world stage,” he said. “These moments are the ones you look back at, though – it is not just Scotland, it is other nations as well. Ireland who celebrated too early because they had beaten Australia only for Australia to kick off and score the try in the corner that beat them to go through to a semi final and go on to win it.

“I know a lot of people go on about luck in sport but I am one of those who believes you make your own destiny. Unfortunately it can be a missed tackle, a dropped ball, a wrong decision, a slack drop goal – or it can be a winning drop goal like Jonny Wilkinson’s and glory comes you way.”

For Hastings, Scotland’s mission is to seize those moments, and make them work for the team – he knows all too well how it feels when the slips come.

“I still look back at the tackle I made on Emile Ntamack back in 1995 when Scotland played France. If I had hit him and stopped him from scoring with the last play of the game, Scotland were on their way to a quarter final against Ireland and potentially into a semi against South Africa.

“In my mind I went from a hero situation to zero. Then we came up against the All Blacks and that team scored more points against them than any other team at that time in history but it was not good enough to beat what was undoubtedly an incredible All Blacks team.

“That is what I mean about taking chances. When you get that chance, you make that tackle, you dislodge the ball —France don’t win the group, Scotland do because that tackle was made. That is the difference between winning teams and losing teams, I’m afraid. It is brutal. I still get feelings about it.

“Every World Cup that is talked about, I still think about that tackle I had on Emile Ntamack. I didn’t nail him — I got him but didn’t nail him. I can still feel him hit me, I can still feel that stutter when I hit him. If I had absolutely nailed him, that could have been Scotland on a different path, just as it could have been when Gavin [Hastings, his brother] missed that penalty in the semi final [four years earlier].”

That is undoubtedly one of the great “what ifs” in the history not just of Scottish rugby but the whole of Scottish sport. Scotland were Grand Slam champions, having beaten England at Murrayfield in en epic encounter the year before. Both teams had been made to battle to reach the semi final, to be staged back at Murrayfield. It turned out to be one of the great heartbreak moments.

“In '91, the side was hugely, hugely experienced with the experience of a Grand Slam season and a very successful tour to New Zealand the previous summer,” Hastings recalled. “People will be pointing the finger at Gavin [Hastings] if he had struck that goal to go 9-3 up with 20 minutes to go then the result might have been different and Scotland might have got to a final but we needed to take that penalty. We will never know what the outcome would have been if he had because the chance was lost and at 6-3 England got back into the game and won it.

“England’s comeback came from supreme confidence as well. They had beaten France the previous week and had come to Murrayfield knowing what they had to overcome from the previous season. They took their chance.

“You don’t dwell on it, you move on but in World Cups, they are hard pills to swallow. Nobody underestimates how tough it is. If you think back to four years ago, having beaten Georgia and Romania in tight games, Scotland played Argentina in a game they controlled for so many minutes and then [Lucas Gonzalez] Amorosino scored for Argentina – 30 seconds of switch-off; that is the difference between winning in a World Cup and losing.”

Seizing the moment is the challenge for the current side. “They have to take their opportunities. Scotland will get chances to win games but they have to take them. They can’t afford to miss passes, they can’t afford to miss touch at crucial times, as they did in the Six Nations, for example,” Hastings said.

“For me, for Scotland this time round, it is about Ross Ford playing his best-ever rugby, it is about the Gray brothers [Richie and Jonny] putting in man-of-the-match performances, about Dave Denton being back to his best, about Greig Laidlaw firing that ball out to Finn Russell playing with all that exuberance and confidence.

"It is also about a clear head from our attacking backs, the likes of Stuart Hogg, the likes of Tommy Seymour scoring tries and taking chances.

“I think everyone can see the improvement under Vern Cotter and I don’t think you can underestimate just what the wins over Italy have done, given confidence. The performances against Ireland and against France have shown that this team can take their chances, it is a question of doing it in a World Cup environment.

“It is the most exciting, exhilarating time of your life, it really is, especially when it is so close to home, within your own country when suddenly that focus and anticipation is there.”

Although people often remember the mistakes, there have been plenty of glory moments as well, such as Tom Smith scoring in the 78th minute to beat Fiji in 2003, Chris Paterson’s faultless kicking in foul conditions to beat Italy in 2007 and Matt Duncan’s heroism as he levelled the scores against France in 1987 with blood streaming down his face.

Relevant to this year, there is also the performance against Samoa – Western Samoa as it was called then – in 1991. They had beaten Wales and were supremely confident but the Scots out-thought and out-fought them. If they meet Samoa again this tournament, Hastings is confident they are capable of doing the same again.

You remember the disappointments, but those moments come in both flavours: good and bad.