Last week I travelled to Lausanne to cover the International Association of Athletics Federations Diamond League meeting there, and as I walked down in blazing sunshine from the station to the athletes' hotel by the side of Lake Leman, I passed cafes full of intent television viewers. Switzerland were playing Sweden in their World Cup match of 16.
On a stretch of grass by a junction, family groups sat at trestle tables in front of a big screen, drinking, eating, enjoying the sun - if not the way the match was going.
By the lake itself, a FanZone with a far larger screen heaved with supporters for whom excitement, in the face of obdurate Swedish defence, was already morphing into resignation. But nobody was leaving.
Three days later, my return journey took me through Paris, and as I emerged from the Metro into the dazzling bustle of Boulevard Edgar Quinet, my senses were assailed by a huge roar to my right - and, a fraction of a second later, to two others across the street.
Albeit that live streaming - legal or otherwise - probably explained the time lapse, the prompt to the thousands of French supporters settled in front of TV screens in the bars and open-air restaurants along the route was identical - Raphael Varane had headed France into a 1-0 lead in their World Cup quarter-final against Uruguay.
At such moments, huge groups of disparate people come together. And if they are sitting in the sun with a beer in front of them and a face daubed with national colours, so much the better. Such is the power of football, the power of sport…
England followers who watched Gareth Southgate's enterprising young side come up marginally short in last night's semi-final against a guileful Croatian team will have been left - in the sudden-deathless words of that inspired Englishman John Cooper Clarke - "feeling like a sucked and spat-out Smartie".
It is just the players who will be coming home - but they have done their nation proud at a time when it is finding little of which to be proud of in its political life.
Fleetingly perhaps - although some memories never diminish - sport can offer society models of aspiration. For French society in the past weeks there has been a rapt focus on a young, multi-racial unit working harmoniously towards a common goal. Who knows how that alters perceptions, re-orientates opinions?
At a more measureable level, TV viewing figures in England have pointed towards a more immediate change. Almost 24 million viewers tuned in to watch them win their round-of-16 match against Colombia, but that number fell to almost 20 million for the quarter-final.
The interpretation on that figure is that it reflects the number of fans who headed out to watch the second game in pubs or on public screens that were set up around the country.
Given that the English viewing figures for last night's semi-final were pre-estimated at 37 million, one can only speculate on how many overall were watching.
When the World Cup grips you, whichever team you follow, you feel it keenly. And, worldwide, the truth is that no sport grips like football.
Speaking earlier in the week, Croatia's former player and manager Slaven Bilic described how the side's achievement in taking third place at the 1998 finals remained his nation's greatest sporting success, eclipsing basketball triumphs and tennis victories such as that of Goran Ivanisevic at Wimbledon as a wildcard in 2001. "Because football is our national sport," he explained.
For the fans of Croatia and France, the 2018 World Cup remains electrically alive.
Croatian Prime Minister Andrej Plenković posted a photo of the team celebrating in the changing room after the game.
"You left your heart on the pitch and deserve to be in the World Cup final," he wrote.
A huge Croatian flag was unfurled in Moscow's Red Square in the hours leading up to kick-off, while one fan told CNN that 15 extra planes had been chartered to fly fans out for the match.
Liverpool defender Dejan Lovren, who played a pugnacious part in last night's victory, recalled on the eve of Russia 2018 his memories of when Bilic and Co lost to the hosts and eventual winners France in the 1998 World Cup semi-final before beating The Netherlands in the third-place match.
"That was one of the special moments I will always remember," he recalled.
Lovren was nine at the time.
Meanwhile, the small but beautifully looked-after village football ground opposite our front gate in south-west France is busier than ever, with boys - and some girls - playing in the goals that remain up between matches minus their nets.
You can hear their excited cries and shouts in the long summer evenings.
For them, as their national side prepares to try and accrue a second World Cup win to set alongside the one it managed on home ground 20 years ago, the magic of possibility is still there. And so they play on, another generation who will always remember these heady days of sport…