Sixteen years separate the super-heavyweight Olympic gold medals won by Anthony Joshua at London 2012 and Wladimir Klitschko at Atlanta 1996.
The fact that they now face each other at Wembley Stadium on April 29 in world heavyweight title fight represents a rare slice of boxing history and adds an extra sprinkle of spice to an already piquant punch-up.
For it is indeed rare that those who have acquired the ultimate Olympic glory at either heavyweight or super-heavyweight go on to box a fellow Olympic champion at the same weight for what is still the richest prize in sport.
Rare but not quite unique. As far as I can ascertain it will be only the third time that this has happened.
Four years ago Klitschko himself defeated the Russian super-heavyweight champion of Athens 2004, Alexander Povetkin, in Moscow.
But before that you have to go back 40 years, to 1973 in Kingston, Jamaica, when the then ogre that was George Foreman, the Mexico City 1968 champion, virtually clubbed Tokyo 1964 winner Joe Frazier into orbit.
Hang on a mo, I hear some ask. What about Muhammad Ali against both Frazier and Foreman? Didn't these clashes feature Olympic heavyweight champions too?
It is a common misconception, for Ali's Olympic title was won as a precocious 18-year-old light-heavyweight in Rome 1960 when he was Cassius Marcellus Clay.
It was the same when American Pete Rademacher, Olympic heavyweight champion from Melbourne 1956, met world champion Floyd Patterson in his first pro fight. Patterson's own Olympic title came as a middleweight at Helsinki 1952.
Two other Olympic heavyweight champions who did meet in professional combat in 1991 were Lennox Lewis, the Seoul 1988 gold medallist, and Tyrell Biggs, the champion at Los Angeles 1984. However, neither held the world title at the time, although Lewis was later to do so.
And so to April 29, 2017. Joshua, 27, heads into the contest with Klitschko giving away 14 years in age and 50 contests to the vastly more experienced 41-year-old Ukrainian. But he believes his comparative youth will give him an edge in one of the most fascinating world heavyweight title fights in years.
It sees Big Josh, the reigning International Boxing Federation (IBF) world heavyweight champion, defend his title against a legend of the sport. The vacant International Boxing Organization (IBO) championship, as well as the World Boxing Association (WBA) super title, will also be on the line in front of a record crowd of 90,000.
"I hear a lot about age, but it's a young man's sport," said Joshua, born in Watford of Nigerian parents, to Sky Sports' The Gloves Are Off. "He has his experience, which will be good to see him through a few rounds, but then youth, excitement, adrenaline and speed will start causing issues.
"You can't prepare for what I bring to the table, no matter how much experience you have."
Hamburg-based Klitschko has held all three world titles and has only been defeated four times in 68 professional fights during a stellar boxing career.
Joshua has been quick to praise Klitschko's positive mentality at his age.
"It's tough for me now and I'm younger," he said. "Imagine I'm around people of his age, and I think to myself, they couldn't do it."
Klitschko sees the contest as being something of a chess match between two equally-matched physical specimens, but vowed to congratulate Joshua if he emerges victorious and be there to pick him up if he inflicts the Brit's first professional defeat.
"You know what kills speed? Anticipation," he said.
"I believe he has a very good analytic mind but there is a difference between him and me. We will see how it goes. We look alike, size-wise (both are 6ft 6in) and the reach is the same, biceps, punch power.
'We can name a lot of things and the more I look at it there is a copy. Different but a copy. But I am obsessed with my goal to lift my hands after the fight when I leave the ring.
"This obsession is a threat going through my heart and mind. This is like a match game in chess, the other putting the other on the other side to try and use the weakness.
"The better fighter, the better pugilist is going to win. Good if it goes early, good if it goes the distance."
He has told Joshua: "If you win, I will congratulate you. If you lose, I will help you to come back."
When they won their respective Olympic titles their only reward was the circular piece of gold bullion. On Saturday week they will each be enriched by some £10 million ($13 million/€12 million), thanks to that 90,000 sell-out crowd. Ticket prices have ranged from £2,000 ($2,500/€2,400) for VIP ringside downwards, with Sky's pay-per-view costing a somewhat steep £19.95 ($25.45/€23.75).
With the 90,000 tickets sold almost as soon as they were printed, the fight hasn't needed hype or hoopla to sell it. Unlike Klitschko's last encounter with the now suspended Tyson Fury, the build-up has been refreshingly polite and respectful.
The multi-lingual "Dr Steelhammer" has always been a man of charm and dignity and unlike potty-mouthed Fury, Joshua is not into the business of gratuitously slagging off opponents.
When he and Klitschko appeared together on The Gloves are Off, a show where insults are usually traded like left hooks in the ring, it was more a love-in than a glove-in.
Undoubtedly, this by far is Joshua's toughest test.
The most experienced heavyweight boxer in the world, full of guile and savvy, against a young man who, despite his World Championship status, is still a relative novice.
The 2012 Olympic champion has steamrolled his way through his 18 professional fights since joining the paid ranks a year after winning gold in London, beating all his opponents by knock-out or stoppage. But none have been anywhere near Klitschko's league, including those in his IBF title fights.
In fact, Joshua has only been taken beyond the third round twice in his pro career when Dillian Whyte and Dominic Breazeale both took him to the seventh. There can be little doubt this will be his toughest test to date.
That said, Klitschko hasn't fought since an astonishingly lacklustre performance against Fury saw him lose his WBA, IBF and WBO titles in November 2015. He was uncharacteristically timid and negative.
The Ukrainian aged that night. He appeared nonplussed and bamboozled by Fury’s dancing, prancing and jabbing. He simply did not know what to make of an opponent bigger than himself. I suspect he will find the more orthodox Joshua easier to fathom.
And surely he can never box as badly, or make the same mistakes again?
He vows to atone for that deeply embarrassing night in Dusseldorf. But has he been away from the ring for too long?
No-one doubts his fitness. His training regime at his luxury boot camp high in the Austrian Alps is relentless.
I doubt there is a more physically attuned 41-year-old in the world.
We know Joshua can punch and box but little else about him is evident. Can he take a decent whack? Can he last the championship distance of 12 rounds? Will Klitschko know too much for him?
Joshua, a supreme athlete, has never been beyond seven - so should the bell sound for the eighth and Wlad the Impaler is still in there punching, it will be very interesting. Could it toll the end of Joshua's brief reign as a world champion?
The bookies say otherwise, making Joshua 2/5 on. But I would not be surprised to see Klitschko snaffle a points win in this intriguing battle of the Olympians.