The All Blacks are basically the Dr Whos of the rugby world. For those who've never seen TV in the past half century, Dr Who regenerates every three or four years rather than dying.
To achieve that feat in rugby terms, you need to be blessed with a constant production line of new talent, and the nous to realise that the old generation is getting, well, a bit old.
When you can't do that, you end up with teams that have great eras, but then fall into holes. The dreaded rebuilding has to begin. Some nations are always rebuilding.
That makes it sound easy for New Zealand, but it isn't. When do you bring through the new talent, and how. How do you blood that new talent so they learn about test rugby, the highs and lows. When does the new guard replace the old.
Clearly there's a bit of structure about how it's being done. The squads as they are unveiled during the year typically include bolters - also known as players you've not heard much of, but who someone, somewhere, has been watching closely. Other bolters are those who are clearly stars in making, but who are accelerated into the top flight earlier than you'd think (Asafo Aumua!).
Now not every bolter or new face kicks on. In fact, it would be a big team if you put together those who have been tried and then slipped back out again for whatever reason.
For fans it can be a bit bewildering keeping up. You might even hear the odd huff and puff about devaluing The Jersey. Just exactly who is that prop from Dannevirke who you've never heard of.
Just look at the latest Northern expedition. I think there are 37 players in the squad, then another five add-ons to cover the French leg (they'll have played in the BaaBaas game against the All Blacks). That's 42. In Dr Who terms, it's lucky the Tardis is very, very big on the inside.
Still with the Northern gig, and a week before the All Blacks, the cock-a-hoop Aussies play the Barbarians.
The nice twist is that the BaaBaas are being coached by 76-year-old eternal motor mouth Alan Jones.
He wasn't too shabby a coach last century, you'll recall and he's promising to have the BaaBaas trying some of the old styles backline formations of his heyday. You may be old enough to remember those tight little Aussie back moves, with slick passing, that raised hell with the All Blacks and other teams for a while.
Mark Ella reckons modern back moves are rubbish (well, he actually said that in stronger terms) and he was a genius player, but you can't help fearing for the outcome when 1980s disco meets 2017 heavy metal.
It's a great bit of theatre though, and as Michael Cheika noted, there's no way he's getting in a war of words with Jones, who will always get in the final say.
Is this Friday it? Surely it is, surely the Lions will cap a great regular season with victory in the championship final, and a final return to the Premiership after what feels like an eternity.
That's not disrespecting Bay of Plenty, but it's going to be a choking proportion tragedy if the Lions can't seal the deal.
That said, this is Wellington, and the regular email to fans this week pointed out how we've twice in recent years been pipped at the final post - most recently in 2015 when they lost by a single point to Hawke's Bay in Napier. Nothing like settling the nerves . . .
I'll be heading to the stadium for sure because this will be my last chance to see some live New Zealand rugby for a couple of years. My partner and I are heading to Vanuatu on a Volunteer Service Abroad posting to work on a World War Two museum project.
I hope to keep blogging from abroad. I'm told the Vanuatu people know about the All Blacks.
Is there any part of the planet they don't reach in to? That Tardis sure comes in handy.
Lifelong All Blacks supporter Kev has followed the Hurricanes since they began. Last year his faith in them was rewarded when they won the title – they've missed out in 2017, but he'll be back!