Happy birthday, then, Pelé. You are as of this week 73 years old – and judging by the pictorial evidence still a brilliantly sprightly, goat-ishly energetic hypergiant of the sporting firmament. As someone who has been a little worried about Pelé for some time now, or worried specifically about the decline of Pelé-ism, the waning of the Pelé Supremacy, I can only hope Pelé wasn't tempted to compare Thursday's celebrations with, say, his 50th birthday.

On that occasion Pelé got to leap around on top of a giant birthday cake placed in the middle of the San Siro pitch while a costumed choir sang happy birthday dear Pelé, finally descending from his ceremonial Pelé-sponge to play in a Brazil versus the rest of the world match (seriously: this happened) before retiring to a Pelé-specific presidential plinth to do a lot more waving and hugging and benediction-bestowing, the entire spectacle beamed live to a global audience. That was Pelé's 50th. It all seemed perfectly acceptable at the time, possibly even rather elegantly understated.

This week? Not quite so much of a thing. In fact perhaps the most galling aspect of Pelé's austerity-scale birthday commemorations in the sporting media was the undercurrent, crushing but still undeniable, of a need for the first time to explain exactly who he is. "The former Brazil striker" … "Considered by many to be …" That kind of thing. Thankfully, we haven't quite got around to "Seen as the Cristiano Ronaldo/Frank Lampard/Andros Townsend of his day". But it is only right to face up to it. The old certainties are fading. The basic concept of "Pelé", the unassailable fact of the Pelé-shaped universe, is something that does now belong decisively to the past.

To the younger generation this will be prehistoric news. Pelé has for some time been a cumbersome icon, deprived of the cultish appeal of the marginalised or the overlooked, and existing instead as a pachydermic mega-brand, dad-ishly passé, a kind of footballing Hotel California. But for those raised in an era when Pelé filled the skies it is still something of a shock. Buoyed further by the Pepsi-Coke rivalry with Diego Maradona – Diego was cooler: but Pelé is, in the end, Pelé – he was simply a staple of life, like pasta or television or the internal combustion engine. More than this he seemed also to mean something. Here he comes, Pelé in flared crimplene disco-slacks, shirtless, strumming the guitar, twirling a ball on his raised index finger, straddling the globe like a doe-eyed sporting Jesus, a messenger of some nebulous but seductive notion of pure love-beaded 1970s football power.

And really Pelé-ism was a surprisingly serious business in this country. Never mind that Pelé himself was never quite the force of pure imagination he was sometimes painted, looking now more like the first really modern footballer, the first to make the ball look so light, to put his entire intelligence and physique into those teasing jinks and nudged passes, the whumping shots, when pretty much everyone else still seemed to be carrying out a rather earnest military PE lesson. Never mind that the notion of the joga bonito itself, part-imposition, part wilful self-mythology, was always a bit of an illusion. Pelé and Pelé's Brazil spoke clearly to one half a dialogue that ran right though English football. On the one hand the pragmatists, the direct football cult of the FA coaching schools, who declared we had nothing to learn from the Brazilians. On the other the free-thinkers, the progressives, for whom Brazil's 1970 World Cup win stood as a kind of footballing Woodstock, a broader triumph of the human imagination.

In this version of events Brazil represented a notion of escape from an older, stuffier world. I spent some slices of my own childhood in São Paulo, where at times you would come across a particular type of ex-pat Brit: twinkly, safari-suited geezer-businessmen with a sense of good-time adventure about them, men who seemed to be fleeing something restrictive and class-bound in their own country and who would talk in sandpapery tones late in the evening about the beaches of Bahia, the wilds of the interior and of course Pelé. "He was like a bull," I remember one middle-aged helicopter salesman telling me. "You could kick Pelé. You could kick him all you wanted. He'd beat you with skill." For these men Pelé and indeed Brazil itself were a source of exhilaration, bundled up together in some way with disco music, escape from suburbia, not having to be in the army, dancing to samba music in a beige safari suit while smoking a cigar, and generally escaping the mannered mediocrity of square-headed post-war Britain.

It is, to be honest, a little embarrassing looking back now at the sheer longevity of Pelé-ism, not to mention its basic seriousness. What can I say. There was no internet. We had no access to eastern Europe, Africa, the Balkans, other than in glimpses every four years. Plus pre-modern celebrity was a more elephantine thing, less mutable. Once you became Stanley Matthews or Bobby Charlton or Puskas, that was it. You were in. Whereas the sporting world is hungrier now, and more diffuse. Fresh Pelés, or mini-Pelés are minted year on year. Even when Lionel and Cristiano are gone the gong will clang just as loudly for whoever will follow.

Not that the idea of footballing ultimacy will ever die. No doubt 20 years from now there will be a World Cup in Spain and grey-bearded hipsters, still fiddling with their clanking, cobwebbed iPhones, will emerge to marvel at this spiritual home of the modern game, regaling one another with historic pass completion statistics and generally reliving a football culture that also spoke eloquently to its time, carrying a sense not of noble primitivism but of systems and applied intelligence, of a distinctly European kind of coherence.

These things run deep and my own guess is for those who remember any of this there will always be a shadow-Brazil flickering behind the mundane yellow-shirted reality. Just as its greatest icon will continue to exist, it is to be hoped, in undiluted form, retaining to the end that undimmed Pelé-power, the indissolubly noble Pelé of the imagination. Bring out the giant cake again. Viva Brazil! Viva Pelé!