It comes from the top-down.
Like all industry-leading organisations, the standards expected are those set every single day.
It starts with the coaches and continues with the senior players, most notably the captain.
It was Isa Nacewa's professionalism that had the second tier of Leinster's lot, behind the regular internationals, standing to attention.
The announcement of Jonathan Sexton as Leinster captain for the season ahead might just be an audition to succeed Rory Best as Ireland skipper after the 2019 Rugby World Cup.
After all, there are those out there who believe Sexton's combustible nature is not aligned with the kind of captaincy that curries favour with officials.
This was recently highlighted by the out-half's confrontation with Pascal Gauzere in the third test against Australia in the summer.
"I am captain now. You have to talk to me," he told the Frenchman when Peter O'Mahony was removed due to injury.
"I know you hate me. But, you have to talk to me."
Sometimes the frustration Sexton feels with referees is understandable as the out-half is a stickler for the details of the lesser-applied laws of the game.
Oftentimes, there is merit to what he has to say and it can shine a light on the inadequacies of referees, undermining their authority and, ultimately, their confidence.
When any referee walks to the middle for a big game, he knows full well that Sexton is going to scowl at them for not doing their job as quickly as he would one of his players.
That is one of the reasons why Leinster's winning culture has been transformed back into the juggernaut it once was between 2009 and 2012.
While Nacewa is gone, Sexton remains in place to keep heads straight and feet on the ground.
There is no chance the glory of last season will impinge on this one.
"It is unusual," noticed James Tracy.
"You look at the likes of Johnny, someone like that, they could have sat back and said, 'we've had a great season' and not kicked on.
"They came back and - it was said in one of the meetings - was it Tom Brady who said, 'my favourite Super Bowl ring is the next one.'
"It is brilliant for the refocusing of the mind and moving on to the next one. It is driving that legacy on to the fifth star and, obviously, retaining the PRO14 as well."
The only way to savour winning is to keep on doing it.
Sexton knows that. Rob Kearney, Cian Healy, Scott Fardy, Sean O'Brien and others too.
"We are all lucky to be in the environment that we are in, surrounded by such world-class players," said the hooker.
"It is the ambition. It is not just lip service because you see they live every day.
"They are going out there to get better and win something else."
Of course, Tracy has Sean Cronin and Bryan Byrne for company and competition in what will be a lively three-man contest this season with Academy hooker Ronan Kelleher lurking behind them.
Byrne received a heavy dose of media attention this week for two tries, the first from holding the ball at the back of a maul and the second from a drive to the base of Cardiff's right, post last Friday night.
Tracy is on something of a mission to make up lost ground.
It wasn't that long ago that he had moved ahead of Cronin at Leinster and Ireland.
"I want to be starting for Leinster first of all," stated Tracy.
"After that, I want to get myself back in contention for the Irish squad."
The three test series in Australia left an impression to go with that of the Grand Slam.
The positive impact of Niall Scannell and Rob Herring didn't go unnoticed in a 'that could have been me' series for Tracy.
"It is bitterly disappointing seeing the lads do so well and not being involved.
"But it also gives you a hunger to get back and a goal to strive towards."