Even if they never meet, the lives of American gymnast Simone Biles and the Irish swimmer Mona McSharry have overlapped and caught the wild extremes of the Olympic experience over just 48 hours in Tokyo.
Biles' decision to withdraw from her team gymnastics events will become one of the associative images of this fortnight in Japan. Her decision has arguably generated more attention than the path she was expected - obligated - to follow by sweeping to team and individual gold.
Every Olympics has its unofficial figurehead. It was Michael Phelps in Beijing, Kobe Bryant in London. In Rio, it was Biles. Since those games, the former testimonies of Aly Raisman and other US gymnasts brought about the trial and conviction of Larry Nassar, the former team doctor, in one of the most appalling and prolonged catalogues of sexual abuse in US history.
The testimonies were courageous and revealed, behind the competitive façade of smiles and sequins and the torrent of US gold medals, an unbelievably bleak story of coercion, intimidation and betrayal of trust. Biles later understood that she, too, had been molested by Nassar.
The reputation of the sport’s governing body was destroyed in America. Biles became its paragon, its unofficial spokesperson, its saviour. The role was not much fun. She is 24 years old, a veteran in gymnastics culture. The circumstances of her introduction to gymnastics are well-documented and speak of the underside of American life.
At the end of the day I'm such a huge athlete but who am I?
Her early childhood was one of extreme poverty, including food shortage. She was effectively adopted by her maternal grandfather and his wife and introduced to gymnastics. America has 330 million people but the population of elite gymnastics is little more than a village. Within that rarefied world Biles became a household name while still a child and her brilliance was transformed into a fireworks display of athletic brilliance in Rio.
So the sight of her walking out of the arena, mid-competition, was shocking. To the untutored eye, it looked as if she had landed awkwardly after executing what is technically called a two and a half twisting Yurchenko. It turned out that she had lost her spatial bearings as she executed the move.
You sometimes hear of ball-sports athletes describing how, in the process of jumping for a ball, something causes them to lose cognizance of where they are in relation to the ground and they return to earth awkwardly. It can lead to twists, ruptures, leg breaks: serious injuries. And they are usually vertical and no more than three or four feet in the air.
Gymnasts like Biles operate at three times their body height, performing complex manoeuvres at unnatural velocity and all the time concentrating to make sure their body alignment is perfect: no slackness, no untidy landings. “Like diving into a pool without water,” was the apt comparison of a team-mate this week.
The consequences of trying to compete without absolute confidence in spatial bearings could be catastrophic for the athlete. So Biles stopped performing. The international response was convulsive and combined ardent support with the predictably poisonous.
At the heart of it, though, was the fact that the arguably the best ever gymnast is in a conflicted state about her sport. “I truly do feel that I have the weight of the world on my shoulders at times,” Biles wrote before the Tokyo games. This was partly down to the absolute dysfunction within US gymnastics culture. But also: what pressure.
Making it to an Olympic final is not an international news story. Every day the games produce a blizzard of winners and losers: look at the medal table already. But the presence of Mona McSharry in lane eight of the women’s 100 metres breaststroke final became one of the most heartening Irish stories - sport or otherwise - of this year.
Irish swimming has been devastated by its own internal scandals in the not-too-distant past. It needed an uncomplicated story in which people could believe. McSharry’s path to that Olympic final was, by modern standards, unorthodox.
Living in Grange in County Sligo, she joined Marlins swim club in Ballyshannon, county Donegal, which has a long-established swimming tradition. When it became apparent that she had exceptional abilities, there were pressures to change her training regime. But she preferred to stay local. Training in a 25 metre pool meant devising an unusual programme.
She operated as an elite amateur athlete in a pool that was also used for social swimming. But the compensations were amazing. She could walk to the pool after school in Ballyshannon. She could hang out with her friends. She could head across to the café in Slevins for a bagel after training on evenings when her parents were coming in to collect her. She could, in other words, live a normal well-adjusted life.
On Tuesday, Grace Meade, who has been coaching McSharry since she started, spoke with Eoin McDevitt on the Second Captains show. As they went through her weekly schedule, Meade explained that they always finished early on Saturday mornings so McSharry could essentially have the weekend free from the water and return rejuvenated at 6am Monday morning.
McDevittt was audibly and understandably surprised. The presumption is that all serious swimmers spend all available weekend hours clocking up lengths. But no: here was someone who became a world junior champion in her sport without having to abandon the rounded sense of what it is to grow up. Afterwards, on RTE, swimming analyst Earl McCarthy said that whatever training regime McSharry and Meade had devised should be emulated.
He wondered if it couldn't be replicated in other swimming pools in other Irish towns. And it was clear from McSharry's sparkling television interviews in Tokyo, here also was someone still brimming with enthusiasm for her sport. McSharry is in university in Tennessee now, where the facilities are superb and, one imagines, the weekends are not free. But she is also an adult and excited at the thought of the Olympics in three years' time in Paris, when the ambition will be to win a medal.
Swimming and gymnastics share a culture of unforgiving immersion. They may have team dimensions but they demand prolonged periods of solitary training.
How many millions of laps has McSharry swam just to get to that point during the week, when televisions across Ireland were turned on at three in the morning to watch her swim through the 66 seconds of Olympic waters? God only knows. But it is obvious that through her parents and coaches and friends, they achieved for her the perfect balance between excelling and living her life.
Shortly before the games began, Juliet Macur of the New York Times wrote a revelatory interview piece with Simone Biles. "Honestly, probably my time off," she said when asked about the happiest time of her career.
She has always pushed the boundaries of technical difficulty - and danger. Although she has been relatively injury free - a broken rib, wrecked shoulder, shattered toe - she has said she lives in constant physical pain. She hadn’t lost an all round event since 2013 so the assumption was that she could just glide on automatic through the turmoil in Tokyo and tick off another haul of golds. But something gave.
“At the end of the day I’m such a huge athlete but who am I?” she said in that interview. “If you take that mask off, you know, who will I be? I’m still trying to find out.”
It’s a question that was allowed to breathe within the framework set out when Mona McSharry was training in the northwest of Ireland to become an Olympian. And given the sacrifices demanded of all Olympic athletes it is probably the most important question of all.