McGrath is thriving once again after going extra mile to regain his place in Leinster's line-up
Last summer, it must have seemed to Jack McGrath that his mastery had become an island all of itself as the Irish regular returned, exultant, from a defining Lions series debut.
But an island must be trimmed and watered and nourished, and when he returned home he found himself bereft.
Sidelined from the action, the one-time protégé found himself cast adrift as a rejuvenated Lions predecessor thieved his pre-eminence, first in Leinster blue, and then in Irish green.
Life has taught the 28-year-old not to treat sporting setbacks with furious grievance, but his professional pride still stung.
His supremacy now temporarily a desert island, he knew not merely how to return to his former self but, more importantly, from where to begin.
Uncertainly advancing that a "few different things" held him back, he is pinned down to narrow the road to redemption.
"Just more fitness," he said, a simple declaration but one masking a number of factors. "At this level, if you are a little bit behind the pace, you stand out in a negative sense. For me, it is staying on top of fitness."
The IRFU's much-touted player welfare system remains the envy of the world but is not without flaws; its remarkable science can often mask human needs.
Despite his summer exertions, and those of previous years, McGrath felt he needed the reality of game time, whereas decrees from above directed he remain off the field.
His scrum coach at Leinster, John Fogarty, said: "The big rigs, the front five players, they need to truck.
"You see it across the provinces, where all those big lads need to be playing games and they need to be playing as regularly as they possibly can.
"Now, you overplay them and they'll burn out, but he probably came back not exactly where he should have been at the start of the season, which led to maybe a slower start than normal."
McGrath nodded in agreement.
"I probably didn't have enough game time, I wasn't doing enough extra sessions," conceded the man who was picked on 41 out of 44 occasions by Ireland boss Joe Schmidt - and only then rested - before being overlooked in November.
"When I came into November, I was probably a little under-cooked and selection didn't go my way. I parked that and I have a regime now that I find is working for me in getting back to the best of my ability.
"I need three or four games and I think I had two or three games, I can't really remember now. I was just a little bit under-cooked. It happens. I'm not dwelling on it."
Other players have in the past cavilled at the stringent nature of the player welfare system but, for the employees, whatever is bidden must be observed.
"It's out of your hands. You can't go and tell Leo Cullen I want to play X amount of minutes," said McGrath.
"You've to make up your minutes elsewhere, and that results in maybe doing an extra few running sessions a week or a circuit or something that's beneficial to your game."
And so, as he literally and figuratively seemed to be running around in circles, Cian Healy darted a straight line back into Leinster and Ireland contention, rebooted and re-energised after his personal injury nightmare.
McGrath, it was clear to all, was not merely physically wanting but also mentally suffering with the sudden realignment among the prop stars.
Fogarty continued: "We've talked about it before, from where he's been up for season upon season and summer tours, Lions tours, I think he had a mental drop-off as well. Sometimes that happens.
"It's tough, it's difficult but it's human. Sometimes he probably won't even know that it's happening, where he has a tiny little drop-off.
"And because Cian is Cian and you've got other quality players like Dave Kilcoyne, physical drop-offs or a little mental lapse can lead to losing your place, simple as.
"How he reacted to it has been really impressive. He made himself a good plan with the guys in here, physically what he needed to do, and he's put himself in a good position.
"And then on the other side, the door has been opened a little bit and he's going to get some minutes.
"I think that's a good thing for us, a good thing for Ireland, and it's a good thing for Cian as well. It's important that we're bashing each other in here and they feel that they're in a very competitive environment.
"The head is down and they are working. For us and for Ireland, they're putting themselves in good positions and I hope we can all benefit from it."
Such is McGrath's status, Cullen appointed him captain for the winning trip to Munster before Christmas and, with Healy currently on the naughty step, the St Mary's College man is eagerly stealing a march as the Six Nations, and indeed Saturday's visit of Ulster, hovers into view.
But, typical of his strong mind, his ambitions will not be weighed down by anxiety.
A grind? Nah, this is living.
"No, no. Obviously it's easier when you're winning, you enjoy everything. When you're losing it gets a bit more difficult," he added. "I think the way it is in here, we enjoy training. We're looked after and there's trust between players and backroom staff whether you have to tell them you're okay or not okay. They sort of know. Guys are being well looked after and when we get out on the pitch we know what to do."
In Irish rugby, no man is an island.