Leo Cullen is one win away from the perfect season.
He is one victory away from doing what he could never do as a player and what Joe Schmidt failed to do as a coach.
It hasn't come easily or without suffering as the transition from inside to outside the white lines has been a roller-coaster ride of emotions for a man rarely inclined to show them.
Back in the halcyon days, the three-time Heineken Cup winning captain failed to deliver the League and Cup double in 2009, 2011 and 2012.
Of course, the definition of failure is all relative, as Leinster have kept the winning culture going with League titles in 2013 and 2014.
And then, the slip in standards accrued precious little in the way of achievement.
Matt O'Connor lasted just two years and Cullen was rushed into the lead role after a year as a forwards coach.
By the time Jonathan Sexton returned from Racing 92, he could not hide his opinion about how Leinster's culture had been eroded.
Cullen had the humility and the instinct to reach out to Stuart Lancaster and everything has flowed from there.
Last season, there was the promise without the delivery and Scarlets had a lot to do with it in this competition.
The capture of silverware had been elusive until two weeks ago.
It is little wonder Cullen was seen to shed a tear in the comfort of the coaches box at the final whistle.
He now knows what it takes from both sides of the fence.
That means he has a special insight into managing his men from the European Cup final through to the PRO14 final via the league semi-final.
Cullen took the decision to allow the troops the release of two days of "appropriate" celebration after Bilbao.
He felt he had to let them blow-off steam, to savour the biggest moment in Europe.
He was willing to take a chance on not having enough to get beyond Munster in the last four clash last week.
In the past, Cullen has spoken about the relentless march of the season and how he regretted not taking in the full meaning of the big days he experienced as a player when they came and went in a blur.
Perhaps, this is one outstanding feature Cullen brings from his years as a decorated captain into the all-consuming role as a head coach.
He has been there, done that and has the personal perspective of a player with the holistic approach of a head coach.
Last week, Leinster got away with it against Munster in a way they won't against Scarlets tomorrow.
Recently, Cullen turned to Scarlets PRO12 final domination of Munster rather than the semi-final blitz of Leinster to illustrate the holders' love for the big stage.
"People thought it was a one off," said Cullen about last year's semi-final.
"And then they did the same to Munster in the final.
"It turns out the score blows out even more in that game, to the point where every time they had the ball they looked like they were going to score a try."
This is the final challenge for perfection.