'Wayne Barnes knows his job. I don't expect him to tell me how to throw the ball in' - Best
Yesterday was the day that Joe Schmidt turned his squad over to its captain, Rory Best, whose job it is now to manage the mood as they slowly work up to a crescendo.
An experienced skipper, the Ulster man neatly sidesteps the title talk in his Captain's Run press conference as he focuses on an 80 minutes that could define his team's campaign. Why would you think about England when Wales are staring you right in the face, he wonders.
Instead of getting carried away with the prospect of a decider against England at home next week, Best is firmly rooted in the now.
As he surveyed the scene at the Millennium Stadium yesterday, the memories came flooding back. There have been good days beneath that roof, but there have also been difficult ones.
Two years ago, they started slowly and paid the price. Wayne Barnes was in charge, it was the penultimate game of the campaign and it was Paul O'Connell's team then. They fought back, but a Grand Slam passed them by.
In 2017, it serves as a cautionary tale.
"When you go away from home against anyone, especially here when they have kickers of the calibre of Dan Biggar and Leigh Halfpenny and you give away as many penalties as we did in the first 20 minutes, you're going to be in a bit of trouble," he said.
"From 12 points down, to get back and have an opportunity to draw the game very late on... you know it's really hard to chase down a lead here. We started slowly, Wales started very fast and before we could catch a break we were six, then nine and then 12 points down.
"It takes a monumental effort to switch that momentum, so that is a big lesson for us that the easiest way to have to switch momentum is for you to get momentum at the start. The easiest time to get momentum on your side is at the start of the game."
Ireland's management of Barnes will be crucial. In 2015, he whistled them off the park for not rolling away and infuriated the likes of Seán O'Brien as communication lines broke down.
"He's a quality ref and we know what he's going to deliver," Best calmly explained of his approach to the English official. "He's under as much pressure as we are and myself and Alun Wyn (Jones) will be under pressure to communicate with him.
"But you've also got to communicate in the right way; when you're dealing with one of the top referees in the world, he knows his job. I don't expect him to come and tell me how to throw in. There are aspects of me needing to be beside him, but at the same time I don't need to be telling him how to make every decision."
As with any Millennium Stadium match, the roof featured prominently in the build-up.
With the forecast looking gloomy, Schmidt turned to Best and Johnny Sexton to make a call and they opted for a covered pitch.
"There's a little bit of rain forecast," Best said of the decision.
"I suppose Joe asked myself and Johnny first. When you ask kickers and throwers do they want to run the risk of being wet and windy or do they want to take all of that out of the equation and make sure it's dry with minimal wind, well I wouldn't say it was an easy decision but that was the real reason for us as players."
With Welsh backs against the wall, it's bound to be an emotional occasion and Best's job is to find a balance.
"You don't want to be too much over the top so you actually can't function," he said.
"If you're too emotional, you can't focus on your set-piece or your core skills in the game but, at the same time, in the first half against Scotland, we weren't where we needed to be.
Focused "We were so focused on being at that ruck at the right time we forgot to make an impact at that ruck for example. Look, it's a balancing act and the bigger the games are, yeah, you need to tune in to the whole emotional side of it but at the same time you've got to be careful not to do it too much because everyone knows it's a big game.
"Because it's the next game in the Championship, because of where we're playing and how tough it's going to be, we know that we need to start well because Wales are going to come out of the traps hard at us.
"From that side of things, it's been a little bit about making sure we control our emotions and that we're smart and disciplined but, at the same time, we can't be outdone like we were against Scotland.
"The really good thing about Cardiff from our perspective is the drive from the hotel to the ground, it's almost like a pedestrianised zone the whole way and there's so many people.
"You go and you see how many people are outside and you get in and have a quick walk around the stadium and there are loads of people inside and you just wonder where everyone goes and how they all fit in. That's all part and parcel of making big weekends special.
"It's a really tough atmosphere to play in but it's an exciting one for players who want to challenge themselves."