Cameron Smith's unquenchable thirst for self-improvement and a remarkable functional capacity to play rugby league are the secrets to his indestructibility, says Kangaroos elite performance manager Troy Thomson.
As the 34-year-old Kangaroos captain prepares for his 55th Test in the World Cup semi-final against Fiji, NRL.com spoke to Thomson about the qualities that have enabled Smith to play at such a high standard for so long.
Thomson has a lengthy association with Smith in a training capacity, stretching back to his days as a Norths Colt (in Brisbane) and then for a decade at the Melbourne Storm.
When Smith's former teammate Matt Geyer cracked the joke about him being "a footballer in an accountant's body" it entered the lexicon of ways to describe the Kangaroos captain.
But despite never being one of the fastest, strongest or biggest footballers, in one sense Smith perhaps has the ultimate footballer's makeup, as Thomson explained.
"Functionally, in the sense of his ability to play rugby league, I don't think I have seen anybody stronger," Thomson said.
"In the functional movements he has to do, like in controlling a tackle, he has this innate ability to avoid injury and I think that comes from his vision in a game.
"Many times you think he is going to get smashed, but he can just turn his body due to his game awareness.
"If you look at the way he is built, he is very strong through his core and in rugby league to have the ability to keep that part of his body stable and strong has helped him play footy and kept him relatively free of injury.
"But there is a lot if genetics in there. He has this in-built ability to play rugby league."
The Kangaroos are at the cutting edge of sports science and Thomson said Smith was always the first to put up his hand to try new methods to get that extra edge.
"We tried some new cooling methods up in Darwin at half-time which he hadn't done before but he was the first one to get in at half-time and trial it," Thomson said.
"No-one has played more NRL games than he has but he is still trying to get better. That epitomises Smithy in terms of how he tries to improve himself all the time, and that to me is his greatest characteristic.
"We were getting into some pools [in Darwin] where rather than getting into an ice bath, we tried it in a shallower pool where the water wasn't quite as cold.
"Basically we were just trying to cool the core of the body. We trialled it through the week leading up to the game and Smithy thought it was really good.
"He leads the way in that regard and Cam buying into that really helps us as staff."
Smith has pointed out in the past that his natural approach to preparation is old school and not New Age.
"He doesn't buy into too much bulls----," Thomson conceded.
"But if he finds something that he thinks will make him better he will certainly take it up if you can explain why we are doing it and the rationale behind it."
The Kangaroos did what Thomson called "baseline neuro-cognitive testing" at the start of this campaign, the results of which will be available in a fortnight.
Those results may yet reveal the secrets to what makes Smith tick as the test essentially examined how the brain works.
"Cam was really interested in that as well and it will be fascinating to look at how his brain functions in comparison to other players, in terms of what his memory and attention span is along with other measures," Thomson said.
"I personally believe that the cognitive training and cognitive improvements we can have in players is going to be the next big space in sports science in coming years.
"You can start developing training protocols that can develop areas that can be improved on. It might help your attention span, memory or spatial awareness."
Thomson has no doubt Smith, with 358 NRL games to his credit, will reach the 400-game mark.
"In my mind, I have no doubt he can. I don't want to put the mocker on him but I'd love to see that happen," he said.
One of the reasons for that confidence is because Smith shows no signs of trying to take short cuts in his twilight years.
While some films can be modified for TV, there is nothing modified about Smith's training with the Kangaroos. You won't see him reaching for the ''veteran's card''.
"If anything, we have to hold him back so he doesn't do too much," Thomson grinned.
Thomson said it was a credit to the high performance and coaching staff at Melbourne that Smith had been able to evolve as a player and athlete, but added that "the onus is definitely on him".
"He is up there with the best I have seen in terms of his preparation," he said.
"But the enduring characteristic throughout his career is that he has always been a good bloke. He is just so humble.
"I tell a story of him meeting some friends of mine after an Origin and him sitting around at the hotel having a chat until all hours of the morning. For those four or five guys it was the highlight of their life. They still talk about it."