The temptation is to assume that Bastian Schweinsteiger entered decline the moment the final whistle blew in Rio de Janeiro on July 13, 2014. Actually, it probably began earlier. It made it all the more remarkable that he ran 15 kilometres in 120 minutes, staving off decline and resisting Argentina alike. In the history of the planet's most popular sport, only 20 people can say they have been the best player on the pitch in a World Cup final. Schweinsteiger is one of them.
Events of that magnitude always have a significance. For Schweinsteiger, his body weakened by ankle injuries, his tournament having begun on the bench, his record featuring semifinal defeats, this had still more. It was his third World Cup and, while his international retirement came two years later, it always felt as though there would be no fourth. It was his last chance, his final crusade. It was, too, for captain Philipp Lahm, record scorer Miroslav Klose and their fellow centurion Per Mertesacker, who all curtailed their Germany careers after winning the World Cup. It was a happy ending.
Four years on, it has a pertinence. Part of the World Cup's value lies in its rarity. The standard in the Champions League might be higher, but there is always another year; even the 40-year-old Gianluigi Buffon, whose meltdown at the end of defeat to Real Madrid seemed partly due to the sense this was his final opportunity to win the trophy that had always eluded him, has postponed his retirement. He might have another go, but Italy's failure to qualify for Russia '18 meant his final World Cup came in 2014.
If its four-year cycle means it is inevitable some luminaries will not appear on the global stage again, this tournament stands out: There seem to be more, and they appear more distinguished, than in most prior World Cups.
For the generation born in the mid-to-late 1980s, the men who have dominated a decade, this seems either the last chance or the last when they are near their best. It is not beyond the realms of possibility that an immobile Cristiano Ronaldo is in Qatar in 2022, perhaps hunting down Iran's Ali Daei's record of 109 international goals, or that Lionel Messi will continue rescinding international retirements in a bid to emulate Diego Maradona. But for the winners of the Ballon d'Or in the past 10 years, this is it, the final time they can determine a World Cup while at the peak of their powers.
In both cases, it forms part of a grander narrative of a quest for world domination. Yet it is not confined to them, as a glance at their teammates shows. For Argentina's 30-year-old trio of Angel Di Maria, Sergio Aguero and Gonzalo Higuain, it feels a case of now or never. Argentina's outstanding player in the 2014 World Cup was not Messi but their most capped player ever, Javier Mascherano; he will be 38 before the 2022 tournament and is on his last legs for this one. It would be a less romantic narrative for Portugal's pantomime villain Pepe to triumph but, at 35, he is in the last-chance saloon.
Some of a Spain side spliced together from two generations have already had that crowning glory with the 2010 triumph. Yet some have defined an era, and that era will end. For Andres Iniesta, scorer of the winner in the 2010 final, David Silva, Sergio Ramos and Gerard Pique, this will be a valedictory World Cup. It might be for Sergio Busquets, too.
After Spain's early exit in 2014, their erstwhile colleagues Iker Casillas, Fernando Torres and Xavi can vouch for the problems of playing one World Cup too many; perhaps now Germany's Sami Khedira and Mesut Ozil are at greatest risk of bowing out in such anticlimactic fashion.
But even before factoring those whose countries are such infrequent qualifiers that there is no guarantee they will be afforded another opportunity, there are others who have lacked such defining triumphs and who only have the next few weeks to produce one. For much of Belgium's "Golden Generation" -- Vincent Kompany, Jan Vertonghen, Toby Alderweireld, Axel Witsel and Dries Mertens -- this is surely it. For some of Croatia's most gifted group since the 1998 semifinalists -- Luka Modric, Ivan Rakitic and Mario Mandzukic -- it has the feel of a last outing on this stage.
It is also a first for two of the most potent goal scorers of the 2010s, Radamel Falcao and Robert Lewandowski. With only a lone tournament to make their mark, each might have only two games to go after muted starts. It is a third World Cup for their Uruguayan counterparts, who are both in their 30s, but Edinson Cavani scored a solitary goal each in 2010 and 2014, and Luis Suarez's explosive impact took the form of a red card and a bite.
A quest for redemption should stretch to experienced Brazilians like Marcelo and Fernandinho, who are scarred by the 7-1 loss to Germany four years ago. A last glimpse of the World Cup can be defining: Zinedine Zidane departed in disgrace with his head-butt in the 2006 final, and Giovanni van Bronckhorst, rather than having the perfect goodbye, had to watch Spain win the trophy before his 2010 retirement.
The Dutch defender was a worthy rather than outstanding player looking to script the fairy-tale farewell. Now some of the modern-day greats have similar aims. Their exodus from World Cups could create a void for others to fill in 2022. First, however, there are reputations to be embellished and legacies to be cemented. The tournament is filled with ageing players looking to become the 2018 Schweinsteiger, players looking to add a final epic dimension to careers spent searching for the holy grail of a World Cup win.