But, after more than a decade of playing test football, McCaw is oblivious to the detail.
For him, all that counts is the big picture: the state of his joints, his agility, strength, stamina, speed and general sense of being able to do everything he wants on the field.
In regards to those facets, he says he's the same athlete he's been for the past five years. And who could possibly doubt him?
He may be crowned, for the fourth time, IRB world player of the year this morning, an award his performances would absolutely deserve. He's been sensational again in 2012 - the best openside, the best player and the best captain in the world game.
It is, these days, a national pastime to fret about his well-being and speculate that he is at the end of his physical tether, his decision to take a six-month sabbatical only encouraging the doomsayers. To the layman, McCaw's sabbatical is all about resting ageing legs and providing a window for physical recuperation.
But that's not it at all. McCaw is taking a break to restore his most powerful weapon - his mind. He's seen team-mates and other professionals convince themselves that they have been forced to give it all up by their ailing bodies. But he believes that the body only packs it in because the brain checked out some time before.
"A lot of guys who give up say that physically, their bodies were buggered by the end," says McCaw. "But what tends to happen is that you get sick of the niggly injury side of things and then I think you get sick of it mentally - that is what goes first and the body follows.
"You haven't got that drive to get things right and deal with it. I firmly believe it is the mental side of it, as physically, I am as good as I have been in the last four or five years, so there is no reason why you can't go out and perform if you are enjoying it.
"You have to enjoy the challenge of what is involved because as soon as it starts to flicker, then it is time to go and do something else. I am definitely not at that point yet but who knows down the track?
"So having a break might mean that stays well away. When I looked ahead and saw three full seasons, it did worry me a little bit; I did wonder when I would get that little spell off to make sure that I keep that desire that you need. I felt this was right."
He means he was worried about retaining the mental drive to do all the things he needs to do to continue playing as well as he does. McCaw has been an All Black since 2001 and this morning played his 116th test. He has had 11 full Super Rugby campaigns with the Crusaders and, while he wouldn't swap his life for anyone else's, there has been an element of monotony with which he has to contend.
Professional rugby teams are locked into routines and no matter whether it is the Crusaders, Blues, Cheetahs, All Blacks or England, they all work around the same basic themes. Every week is much of a muchness - the same principles apply, the same drills, meetings, discussions take place again and again.
It is the repetition that finally gets to long servers; they just can't get excited or enthusiastic about what lies ahead. McCaw still loves playing for his country; more than anything, he still wants to be leading the team, wearing his treasured No 7 jersey and pitting himself against the best players in the world. He is no doubt about that.
But to ensure he deserves to be wearing that No 7 jersey, he knows he has to crunch through the hard work behind the scenes and that the thrill of game day is a reward, not an entitlement.
"It feels like a treadmill at times and sometimes it could easily feel like a grind," he says. "But if you start looking at it like that, then it will become a grind. And the upside of all this is that on Saturday, you have the thrill of running out and playing for your country.
"If you didn't do all that hard work, you wouldn't appreciate that on a Saturday. It is a rollercoaster all the time because you build yourself up for a game and then bang ... you get all that and then you have to start again. I think you have to be mentally tough to back up and play consistently well. I think when guys get sick of it, they don't get sick of the playing - they get sick of the churning over.
"Every job, no matter what it is, has stuff that you don't enjoy doing. We all have that and if that, the bits you don't enjoy, becomes the focus, then it becomes a chore."
McCaw's sabbatical is essentially an insurance policy to enhance his chances of not feeling the grind between July next year and October 2015. He wants to play at the next World Cup - that ambition is genuine and, in his eyes, achievable.
All Blacks coach Steve Hansen thinks it will be more likely if his captain spends the next months putting him-self first.
"The World Cup was massive and since then, people have wanted a lot of his time and, to be fair to him, he's very good at giving it," says Hansen. "He's got to be allowed to be able to step out of that bubble, so to speak, and have a bit of 'me' time.
"It's not physical, he just needs a bit of time off from being in that spotlight all the time. I'm not sure where he will be able to go where no one knows him but we will do a bit of research and buy him a ticket."
McCaw's plans are still vague as to what he will do with his time off but he already suspects that by June, when the French come to New Zealand, he'll be bursting to play. He won't enjoy watching the three-test series but that is what he wants; he'd like to be in the stands bursting to be on the field.
He wants the reassurance of taking himself out of the frame and then feeling the frustration that brings. That will be healthy for him, the perfect way to be sure he's not ready to pack it all in.
