'His knowledge is incredible' - Stuart Lancaster hails Johnny Sexton as 'probably' the best player he has ever coached
It is time to recognise the greatest of all Leinster teams in the professional or any other era.
Better than 2009. Better than 2011. Better than 2012.
All anyone has to do is scan the names of the Leicester Tigers, Northampton Saints and Ulster victims of those days to see they do not stand the test of time.
None of them stand comparison with French Top 14 finalists and favourites Montpellier, Premiership champions Saracens, Premiership runners-up Exeter Chiefs or even Scarlets.
Don't forget, Warren Gatland chose ten of the men who were smashed on Saturday as starters to tear Scotland apart in the opening game of the Six Nations three months ago.
In the space of six years, the Champions Cup has moved on, making the accomplishment to capture Europe for the fourth time all the more remarkable.
Leinster had the tenacity and the talent to complete the League and Cup double with a performance to rank with any that has gone before it in Europe this season.
Leinster dealt with the physical and mental demands of the last six weeks with increasing fortitude.
They were most vulnerable in the PRO14 League where the seven-day trapdoor from European kings to an Inter-provincial derby threatened to take their feet right out from under them.
"The big moment really was the semi-final to beat Munster," said Stuart Lancaster.
"You win a Champions Cup final. It was a really tough attritional game and we came out on the right side.
"We got back late on Saturday night. The boys had a few beers Sunday and then on Monday we didn't train.
"Munster had been sat there waiting, lying in wait really, I felt, for the RDS game. That was a massive moment, to win that game the way we did.
"I always felt if we could get to the final, the emotion of being in a final in the Aviva would look after itself.
"It was less about emotional, more about technical and making sure we were on the right page from a tactical point of view, so we could beat Scarlets because we know how good they are."
Great teams are driven by great coaches and great players and there is none better than Jonathan Sexton.
"Of all the players I've coached, he's probably the best," said the former England coach.
"I've coached some brilliant players in England, obviously, and worked against players.
"His ability to see the game, his knowledge of the game, his ability to inspire others, to get the best out of them, his drive to succeed and want to achieve things is a challenge.
"But I love the challenge."
There you have it. When a coach walks through the front door at Leinster, he has to know the game inside-out, upside-down, back-to-front.
Or Sexton will smell weakness and weed it out.
"It is his knowledge. It is challenged in a good way," said the senior coach.
"He has been coached by great coaches and he has always wanted to get better himself. He has always wanted to improve.
"By being coached by great coaches and then, ultimately, having this desire to improve makes him (the man he is).
"His knowledge is incredible really," he added.
"When I came in, I brought in some different ideas for him to think about which he has been broad-minded enough to accept.
"And I think his game has developed accordingly.
"His drive to be the best he can be is what sets him apart."
The capacity for Leinster to win a number of ways is the sign of a truly great team.
The single most impressive aspect of their game is the ball-handling ability of their forwards, like Tadhg Furlong and James Ryan, along with the willingness of senior players like Devin Toner to evolve their game.
It is difficult to pin down Leinster's game plan and nowhere was this better illustrated than in the playing journey from Bilbao to the Aviva.
Lancaster was asked about the greatest take from this season.
"I think our adaptability in games," he said.
"Last year, we lost in two semi-finals because we tried to play the same way and we came up short in both of them.
"Now, we've found different ways to beat different teams and that makes us harder to defend against.
"That's definitely one thing," he stated.
"For the team to achieve, to win the Conference, which gave us the week off, without having to go through the play-off because of The Champions Cup, was huge for us.
"The boys who contributed towards that, who didn't play today, that's huge.
"To win the Pool and the quarter-final and semi-final - I watched the first-half of the Exeter-Saracens game (in the Premiership final), two high quality teams - and we beat them both.
"We beat Montpellier who are in the Top 14 final.
"We've not done it the easy way."
Lancaster doesn't want it to end here.
"Look at the players, who didn't play - Robbie Henshaw, Sean O'Brien, Josh van de Flier, Fergus McFadden, Dave Kearney, and there's more.
"Who is finishing? Isa.
"With young players coming through, the hunger and ambition to get better.
"Everything starts from zero next season."