'Carbery showing Leinster the way' - D'Arcy
Success must come from failure; buckets of it. And the earlier the better.
Joey Carbery, the latest audaciously talented 10 to roll off the Leinster production line, wasn't yet three when Gordon D'Arcy began his 17-year residency in Leinster blue.
"Thanks for that, jeez," smiles the former Ireland centre. D'Arcy would make a multitude of mistakes in his career, every one of which improved him as a player.
Carbery's baby steps in the pro game, glittering glides for the most part in defeat to Pro12 title heavyweights Glasgow last weekend, were undone by a glaring glitch of his own which, as is the Irish way, was highlighted in red ink to the detriment of all the good he did.
But even his mistake houses the seeds of success.
D'Arcy's acute rugby brain saw merely a decision that was made for the right reasons and which marginally failed to come off, when his pass was gobbled by the rampant Tommy Seymour.
"I looked at it and the decision was right, he was pushing the pass," he says.
"These things happen and in sport sometimes they work for you and sometimes they don't. It was the right decision.
"You can argue he should have gone over the top, but he was trying to push the pass, he was trying to push for the outside. It was a fair old bit of luck that it ended up in Tommy Seymour's hands. I'd be very surprised if he was even thinking about that again."
We recall D'Arcy pushing the envelope in that glorious quarter-final in Toulouse in 2005; had he not done so, Denis Hickie wouldn't have scored one of the province's seminal tries.
"We had a reverse move with Michael Cheika which meant pushing, really hammering out a pass to Girvan Dempsey and Jean-Baptiste Ellisalde missed it by a finger-tip. If he gets that, he is under the posts. Instead, we end up scoring.
"These are the margins you play with. That is the one bad thing he did but in a way it is not a bad thing. He made a decision and he backed himself and a winger got lucky.
"For me, I would be concentrating on how flat he took the ball to the line for Jordi Murphy to go through on that front-door ball. I always love out-halves who make decisions flat on the gain-line.
"And his kicking game, that kick for Zane Kirchner's try was fantastic. We have seen his off-loads, we have seen his balance. I'm glad I don't have to defend against him."
Leinster were often moribund last season; this is the attacking template D'Arcy demands of his former team this term.
"I hope so, I genuinely hope so. Because when they start coming off, you begin to get a bit of confidence and teams then start sitting back from you, because they know that if they miss something, these guys are going to run in from 70 metres for a score.
"You can't afford to be too reckless at the same time. You do need to play a certain percentage. Leinster have to pick their moments, when they go for it.
"And just the end result wasn't what we needed. But if Joey gets that pass, Stuart Hogg is facing a two-on-one, 70 yards from his try-line. That's the kind of rugby you want to see."
Leinster need to develop their game more urgently than ever - and the former centre praises Leo Cullen's influence in inviting Stuart Lancaster to the set-up - as he assesses it is "almost impossible" for Irish teams to reach the knock-out stages in Europe.
Another seemingly impossible task is knocking the irrepressible All Blacks from atop their perch; D'Arcy (left) was seconds away on his last outing two years ago but he now feels the current world number ones are even better than their World Cup winning vintage of 2015.
"I genuinely thought after the World Cup from what I heard about Richie McCaw, how he was so influential in the team, that they had to drop a level," says D'Arcy, who also maintains Bordeaux exile Ian Madigan "must" be involved.
"I just thought with Carter gone, Ma'a Nonu gone, there would be a glimmer. But absolutely not. They look like they're playing better than they were pre-World Cup, which is just a frightening thought.
"We have always been just within a penalty kick or eight seconds from beating them. Playing them in Chicago, if we can be in that right mindset, there could be something on.
"It's going to be cold in Chicago, something they are not used to, not that we will be used to it. If we have that single-minded purpose, an all duck-no dinner approach, catch them on the hop.
"The one thing we've always done under Joe Schmidt is learn from our mistakes. When we lost to New Zealand, we learned from it."
At any level, the learning never stops.
Gordon D'Arcy will join Andy Lee, Annalise Murphy and the Ireland women's rugby team for a Q&A at the Eir Pavilion at the National Ploughing Championships from September 22-24.