Old age is not for sissies, they say.
At Twickenham on Saturday youth will not be for sissies, as those men will fling themselves body and soul into the World Cup semifinal between New Zealand and South Africa, still the game's greatest rivalry.
Those 46 men, in peak fitness, will risk everything in a sport that is as near as it can be to battle.
They will risk sinew, muscle, bone, heart and mind - everything short of life itself and, who knows, if it were asked of them would life be too big a sacrifice?
And then 80 minutes later they will shake hands and even hug the men they battled against - despite the fury of their effort and despite even the disappointment of defeat.
The match will not be a hate-filled war.
The two have met three times before in World Cups.
South Africa just won the Final in 1995 and then won the third-fourth play-off in 1999. New Zealand walloped South Africa in the quarterfinal of 2003.
The people of both lands will know about this match and experience their own level of tension in the hopes and fears of the day.
It is a part of the culture of those countries.
In days when matches between the two countries were few and far between, as travel dictated (and there were racial hamstrings in three New Zealand sides to South Africa till 1970), South Africa led New Zealand.
Those days ended when the world was an easier place for travel.
Then New Zealand pulled ahead and are now 17 matches ahead, which means that the Springboks are closer than other sides, which also means that they are more likely to beat the All Blacks than other teams are.
More than ever before in the sport's history, the All Blacks rule.
The way they massacred the French in the quarterfinal was an example of that. France have beaten them in the past but not this time.
South Africa have beaten them in the past - this time?
The Springboks know full well the lesson of this World Cup - nothing is impossible. The Japanese taught them that all right.
There is no divine right of victory.
But for the All Blacks to lose they will need to be unnerved into error.
For the Springboks to win they will need bodies and minds of steel.
And in victory and defeat there is always the luck of the bounce - the awkward shape of the ball, the surprising refereeing decision, the opportunity grabbed or missed.
It is a game after all.
And rain is likely.
The All Blacks are more used to the wet than the Springboks are, but the wet can often offer or deny opportunities of victory to either side.
On show at Twickenham will be some of the greatest players in rugby history, many to watch and admire.
Players to watch:
For New Zealand: Of the All Blacks you will want to see several. You will want to see Richie McCaw, the most capped Test player ever and - who knows - perhaps in his last Test. Then there is action-man Ma'a Nonu who may just be in his best form ever, and the three unrelated Smiths. There is buzzing Ben, clever Conrad and artful Aaron. Those three mean so much to their side, Conrad perhaps less obviously but then the greatness of his skill is perhaps underestimated for he is the clever player who gives his fullback and his wings the freedom for run while protecting them in tight situations. Those wings are so worth watching - big, bursting Julian Savea and deceptively strong and deceptively fast Nehe Milner-Skudder, a 100 percent man. And we have not yet reached Daniel Carter, to many with long memories the best flyhalf ever in the history of the game. The backs are always more obvious than the grafting forwards but both New Zealand locks, Sam Whitelock and Brodie Retallick, do what locks do with exceptional skill and determination. These All Blacks are a frightening prospect and yet every one of them is human - flesh, bone and weakness. Even the benches are exciting with players like Sonny Bill Williams, speedy Beauden Barrett and ubiquitous Victor Vito on the New Zealand bench.
For South Africa: Amongst the Springboks there is that intuitive, skilful scrumhalf Fourie du Preez, one of rugby's best, and outside of him young (21) Handré Pollard of immense talent who just over a year ago scored two tries against the All Blacks on the day of Pat Lambie's calm, long penalty. Outside of Pollard is young Damian de Allende who can do all an inside centre needs to do - pass immaculately, burst with strength, clever footwork and speed, tackle efficiently and kick if necessary. There is some power in the pack - Duane Vermeulen, Eben Etzebeth, Schalk Burger, Bismarck du Plessis and Frans Malherbe, and then there is the find of 2015 - Lodewyk de Jager, the 2015 World Cup's leading tackler, who is the most productive Springbok in the line-out and a strong runner with the ball. Every player in this match is worth watching. Patriarchal Victor Matfield, burly Willem Alberts, effective Adriaan Strauss and talented young Pat Lambie on the South African bench.
Head to Head Obviously it's team against team, the more direct and cohesive the better. Then there are units - front rows where South Africa (Frans Malherbe, Bismarck du Plessis and Tendai Mtawarira) look stronger than the New Zealand front row (Owen Franks, Dane Coles and Joe Moody). The least experience players in the front row will be up against each other - Joe Moody of New Zealand against Frans Malherbe of South Africa, nine Test caps against 10. Money on Malherbe. In the second row South Africa has greater youth and inexperience with Eben Etzebeth and Lood de Jager up against Sam Whitelock and Brodie Retallick who knows shortcuts and how to get in the way. The All Blacks could well do better at line-outs and kick-offs than their younger opponents, not that the younger opponents will yield without a full-time fight. The post-tackle area has been highlighted and it is here that South Africa will need to be hard and cohesive to live with the All Blacks for whom winning the tackle ball is an ancient art. There are several battles amongst the backs - calm Fourie du Preez against effervescent Aaron Smith at scrumhalf; smooth, experienced (110 caps) Daniel Carter against young, strong, 18-caps Handré Pollard. There will be two big Old Bull vs Young Bull clashes amongst the backs - strong Ma'a Nonu against strong, fearless Damien de Allende at inside centre and on the wings Bryan Habana with 115 caps and most World Cup tries over all against Julian Savea with 39 caps and most tries at this World Cup. Kicking? The main kickers are Handré Pollard and Daniel Carter, and there is not much to choose between them. Both can kick the really hard one and miss the easier one, but Carter kicks off better. Carter and other New Zealand kickers kick much better out of hand in that their kicks are more retrievable and meaningful than Pollard and other South African kickers. There are so many points of interest in this semifinal which has the feel of a Final.
.Prediction: Either team can win - that's obvious. But clearly the team riding the crest of the wave, the out-and-out favourites are the All Blacks who could well win by 15 points or more. Not that the Springboks could not win.
