So much changes and, yet, so much stays the same. As Jonathan Sexton and Ronan O'Gara take it in turns to make their plays to be Ireland's No1 out-half, the man inside both of them, Tomás O'Leary, seems well clear of all challengers at scrum-half.
There was a time when Peter Stinger enjoyed all the benefits that are attached to the label of one of the untouchables. For years, he built a career on an internal drive to realise his potential.
Now, his Munster colleague O'Leary is the man in possession of the coveted green jersey. He will walk out onto the hallowed turf at Croke Park for his 12th cap tomorrow.
While it would be too much to claim he is untouchable, there is certainly a sense of relative permanency about the position he enjoys within the hierarchy of Irish rugby.
"Anytime you get picked for Ireland is a brilliant day. It is great to get the cap. They are hard to come by," he said, in a nod to those who would threaten his living dream.
"There is huge competition at scrum-half with Peter (Stringer), Isaac (Boss), playing very well with the (Ireland) As, and Redser (Eoin Reddan) as well".
For sure, coach Declan Kidney is doing what he said he would do from day one in building a concrete wall of competition for places in which each brick is valued and respected.
The internal combustion engine that is competition for places is gathering pace. It drives all of the players together under the banner of one for all and all for one.
O'Leary knows he cannot let his standards slip. More than that, he has to take them on an upward journey of excellence. He'll need every ounce of his 13 and a half stones against Italy.
"I have only played against Italy once -- last year. They are a very tough, physical side and they are always improving. They are going to be dangerous," he said.
"They are an extremely physical team, very powerful in contact, very good defensively. It is going to be a tough game. We know that. We are going to have to meet the challenge head-on," admitted O'Leary.
To be at or near his best, O'Leary will require a quick ruck ball and a stable scrum from which to launch his own 'lone ranger' raids or his outside backs.
The scrum has been the single most worrying area for the management since the November series. It was shunted, splintered and cracked like an egg by Australia and South Africa.
O'Leary appears to be unconcerned: "The scrum isn't a concern for me. The boys have done a lot of work on it this week. The Italians have a very strong set-piece. But I think we will do well there".
Whether this is wishful thinking or confidence founded on a marked improvement, on the training paddock, from November remains to be seen.
No doubt, France and England will apply a forensic eye on how Cian Healy, Jerry Flannery and, most importantly, John Hayes deal with Salvatore Perugini, Leonardo Ghiraldini, captain in place of Sergio Parisse, and Martin Castrogiovanni.
It will be revealed whether the Irish scrum has been rebooted or is sub-standard. And if the Munster half-back spends the afternoon putting out fires all around him, he will be in for a gruelling Six Nations where Ireland's only obvious weakness will be bombarded everywhere from Croke Park to Stade de France.
He has been around long enough to know that weakness can become a strength, in the same way Munster's scrum took a shellacking from Northampton in the Heineken Cup three weeks ago only to win a strike against the head with a seven-man scrum to survive a siege.
O'Leary, 26, will not need to be reminded how quickly this game can change. Leinster's Kevin McLaughlin has gone from almost unemployable, because of chronic injury, to winning his first cap tomorrow.
Sexton was toiling away in the AIB League this time last year before a twist of fate, through an injury to Felipe Contepomi, and his surging belief transformed his career provincially and internationally.
Of course, O'Leary was made to suffer exclusion from the British and Irish Lions tour to South Africa when he endured a serious ankle injury in the Magner's League last April.
He knows how quickly good can turn to bad and how he must constantly improve and progress so that everything, in terms of his selection, stays the same.