Playing Munster is like a rugby medical - we now know where we need to improve
The privilege of playing in a fixture like Leinster versus Munster is something that is only really appreciated after your career ends.
In the amateur era it was less intense - at the time, AIL provincial club rivalries were more revelled in by the supporters and the players.
Professionalism changed that dynamic in 1995 but the fundamentals have remained the same.
Munster have always looked to starve Leinster of possession and frustrate them at the breakdown.
For years, Alan Quinlan, Frankie Sheahan and Paul O'Connell mastered the art of stepping over a ruck on top of the Leinster scrum-half pretending to the referee that they were somehow onside. This complete 'innocence' is still the same.
Anthony Foley never asked anything from his superb career but to play in the red jersey of Munster like his father Brendan, and fittingly has ended up coaching his province.
All of his knowledge and experience came out in his players last weekend.
The fear of losing has always driven Munster on and a wounded Leinster in a three-quarters full Aviva Stadium would be ideal in their dressing-room build-up.
The senior players on the Munster team - Conor Murray, O'Connell, Ian Keatley and Felix Jones -completely outplayed their opposite numbers.
The aggression at the breakdown was Munster back to their best, but what answer did Leinster have in reply?
People generally talk about game-plans. A game-plan is a strategy that changes from game to game depending on the strengths and weaknesses of the opposition.
It's applied to each game with a view to correcting your own team's recent inadequacies.
It's obvious that Leinster have literally limped through the last few weeks.
There is an unfortunate dependence on the success of previous seasons, but in the first quarter of the campaign, they've lost against two of the three provinces and are yet to play Ulster, who are arguably strongest of all.
It's understandable that plans made during the week on the training pitch may not function at all times in a game. Coaching staff can prepare a team but coaches cannot take the field.
Adaptation during a game is a skill in itself that the top teams in Europe always possess.
From a Leinster point of view, when you have Sean O'Brien, Cian Healy, Jamie Heaslip, Gordon D'Arcy and Ian Madigan pummelling the opposition with their carries, most of the time organised multi-phase backline moves can look outstanding against a punch-drunk opposition.
But when they're not enforcing this go-forward momentum, Leinster are struggling. There has been no ability to shift the balance of power in the game itself over the 80 minutes.
Throughout the derby match, there were plenty of instances that the Leinster crowd would not be used to seeing. Their defence was completely disorganised after almost every first-phase ball.
It was obvious that the breakdown was lost and Munster had the intensity in this area but even out wide and up the middle through the forwards, Leinster were found wanting.
It certainly doesn't help when your out-half throws two intercept passes and spends most of his time kicking the ball down the throats of the opposition, but the most important part of the game for me was Leinster's inability to take advantage when Munster were down to 13 men.
This is a critical lesson that wasn't learned from the Sportsground against Connacht some weeks ago.
As discussed in this column before, when a team opposes 13 men, the emphasis should be to move the ball at all costs and not get caught up in a dogfight on the ground.
Eventually a gap will be found in the defence and therefore the team with 15 men capitalises on the sin-binning of the opposition.
Leinster again failed to do this and didn't capitalise on their numerical advantage.
The positive aspect of playing Munster is that it's like a rugby medical, Leinster now know where they need to improve.
Selection has to find some sort of stability soon on the back of individual performances, of which there were few last weekend save for an inspirational Dominic Ryan in the first half and a hungry Rob Kearney and Madigan.
Sean Cronin had his moments but the rest of the front-row, apart from the Byrne brothers will wish last weekend never happened.
The greatest legacy this Leinster squad gave themselves in the last decade was their ability to push themselves to the highest tier of Europe.
They got there by demanding more from each other on the pitch and then worrying about the result. This expectation of each other struck fear into the opposition. It took years to develop but will take little time to lose.
A trip to Zebre has never held such significance.