Lancaster closes on silverware
Stuart Lancaster's England did not win a Six Nations title. Lancaster's win percentage (61%) as England coach was better than any since Clive Woodward.
England averaged more points (25.5) under Lancaster than any coach since Clive Woodward.
England averaged more tries per game (2.5) under Lancaster than any since Andy Robinson (2.9).
Leinster have embraced the Cumbrian as a teacher, a tactician, a difference-maker.
And every good teacher learns from their mistakes, especially the biggest ones.
Somewhere along the way, the career coach has to meet winning with silverware.
"The perception is that I lost a lot of games in charge of England.
"But, actually, we won a lot as well. We won some big ones, the All Blacks etc, etc," said Lancaster.
And still. For all that, there is a hole in his CV that can only be filled with a major trophy.
"I don't think there is any coach that has gone unbeaten and I don't think you have to go through that necessarily.
"But, it certainly makes you more determined when you have been through it and come out the other side."
And here we are again. Back to 2015.
Not through any fault of Lancaster. It was unavoidable.
The press showed up in numbers to take Leinster's senior coach back in time, to a dark time.
He will be forever followed around by the questions about England's failure at the World Cup until he delivers when it matters, at least on this side of the Irish pond.
Leinster have rescued Lancaster just as much as Lancaster has them.
"To be honest, you want to do it for Leinster first and foremost, the players and the supporters," he says.
It is those closest to him that had to watch the toll 2015 took on Lancaster.
The debt of gratitude can be paid in part in Bilbao.
"From a personal point of view, you want to do it for your family because they're the ones who have supported you through all the tough times," he added.
"My wife and kids and family and friends, that's the motivation for me."
There are those within Leinster who have compared Lancaster to Joe Schmidt for the impact he is having on the new and next generation.
The former teachers share a lot of similarities and a lot of differences, the most striking being the trophy cabinets that have been built for Schmidt.
The Leinster formula has been calculated on the ego-less partnership between Leo Cullen and Lancaster.
"I think our styles are very similar, and very similar in terms of personality," he said.
"I don't think either of us need to, or want to, be front and centre all the time so Leo is happy for me to lead on stuff, and I'm happy for Leo to lead on stuff.
"He's got very high integrity and very good leadership qualities."