THE GLASWEGIAN SKY was filled with 50 shades of grey, the Celtic Park stands empty of everything bar the echoes and the shadows as Johnny Sexton stood and posed. And in those precise moments, with an orderly queue of 13 rivals waiting in turn to get their picture taken with the Guinness Pro14 trophy that Sexton and Leinster lifted the previous May, a realisation dawned that the sun had finally set on a season he will never forget.

“There’s an old saying,” Leo Cullen, Sexton’s coach, said on that Tuesday afternoon in August 2018, “that success makes you weak.” And that was why, on his first public outing as Leinster’s new captain, Sexton, Irish rugby’s serial winner, felt that the time had come to park 2017-18 in the cupboard of history.

Maybe it was the presence of those 13 players on the Celtic Park pitch that made it easier for him to do so. Or maybe it was the haunting memories lurking in the back of his mind of how the years preceding Leinster’s season of glory were unfulfilled and barren. Once he was part of a side who won three Heineken Cups in four seasons, a golden age followed by an age of regret, and this was why on this dank day he spoke about leaving Leinster with a second legacy before he retires.

“We are at a point where we can weigh everything up and make a decision as to how we go forward,” Sexton said.

Little were we to know then that their sense of direction would be easily mapped, their Sat Nav pointed towards Glasgow and Newcastle, where that season’s respective Pro14 and Champions Cup finals took place. They won the first, lost the second but something else happened along the way that season. On 27 April, 2019, Leinster lost to Ulster in the last game of the Pro14 regular season. It is the last time they were defeated in that competition.

So when we reflect on 2020, the 19 wins from 20 games, the six times they won by 30 points or more, the fact that all bar one of their 19 victories were by a score or more, we can now see how so much of their recent success stemmed from the attitude Sexton and Cullen adopted on that otherwise forgettable afternoon in Glasgow.

“We have to do is ask ourselves, ‘How do we get better from last season?’” said Sexton that day.

The answer is by adding new layers of depth to their squad, instructing their players to treat every game as their final. With so many options in their squad, they can afford to punish complacent attitudes.

You saw it for yourself this year, from the opening game of 2020 when they were like debt collectors knocking on a victim’s door, destroying Connacht 54-7 at the RDS, knowing that if you treat Andy Friend’s side with disrespect then there is a danger you will go home with spit in your face.

Garry Ringrose has developed into a key leader at Leinster. Dan Sheridan / INPHO Dan Sheridan / INPHO / INPHO

You remember another win over Connacht, a week when Cian Healy had criticised the western province’s decision to allow retiring captain John Muldoon take a conversion the previous season in a 37-point win. Healy used the word ‘disrespect’ in the build-up.

That day, as his team mates made their way through a grey Galwegian evening and into the narrow tunnel that divides the Clan Stand, where the most raucous of the Connacht supporters congregate, their pantomime villain purposely waited until last.

The Connacht fans made it clear during the warm-up that they disagreed with his opinion. There was no hiding now, as the teams made their way to the pitch. Last out was Healy, who slowly walked past the noisiest of the Connacht supporters, listening to their jibes, refusing to contemplate running until he was 20 yards beyond them. This wasn’t an entrance; this was a statement of intent.

If you are looking for the seeds of Leinster’s dominance in 2020, it’s there in that moment.

They aren’t scared of going to any place, facing any opponent. Every game is treated as a big one.

And it showed in their 2020 results – as they won each of their away games; each of their five interprovincial derbies, all their Champions Cup group matches, their Pro14 semi-final and final.

Only once did they lose – when Saracens came to Dublin and did a number on them, a wake-up call if ever there was one, a reminder that domestic domination is all well and good, but the absolute elite at European level are unforgiving.

That loss left one dark cloud hanging over them, an asterisk next to the 19 wins. Such are Leinster’s standards that the arrival of one trophy, the return of 19 wins from 20 games, goes down as a very good year not a great one – because to them, greatness is measured by winning the Champions Cup.

The 2020 awards go to ….

Player of the year …..Garry Ringrose has matured into a quiet, inspiring leader who has a big-game temperament to go with his obvious ability.

Breakthrough player … Hugo Keenan A nod to Ryan Baird, too, who had a superb impact in 2020 – Keenan, however, is now first-choice with both Leinster and Ireland

Best moment …. Winning the Pro14 title should not be taken for granted. Nor should the fact that Leinster stayed unbeaten while doing so

And the worst …..  Losing to Saracens 25-17 killed their hopes of another double