One of the few delights of getting older is that one gets to enjoy the spectacle of everything the Cool Kids rubbished back in the day becoming, over time, the very epitome of quality and taste while their own favourites descend into oblivion or, worse, ridicule.
Let's think about Les Dawson and Tommy Cooper for a moment. And then let's think of Ben Elton.
Starsky & Hutch, then, say, The Professionals.
Kenny Dalglish, perhaps, then Kevin Keegan.
The Bee Gees, say, then Clive Anderson.
Tom Cruise, then George Clooney.
Dolly Parton and just about everybody who was regarded as preferable to the woman who wrote Jolene and I Will Always Love You - on the same day.
But all those pale beside what is probably the greatest triumph in the taste stakes in 50 years.
Teenagers who, 30 years ago, protected their albums jealously from the sneers and jibes of Metal classmates and New Wave contemporaries, have been able to observe one group's star only increase in intensity over decades of practical retirement. And now, it seems, ABBA are back.
After 35 years, they have recorded two brand-new tracks, the uptempo Don't Shut Me Down and a ballad specifically about their reunion, I Still Have Faith in You. There are a couple of Christmas TV specials planned to showcase the end material, together with a tantalising promise of hi-tech wizardry - all holograms and CGI. All of course in keeping with the quartet's incredible capacity, in hit album after album, to surprise themselves, master marketing and adapt their sound to new generations.
There are doubts, of course. Can that sound stand up as a current, living idiom after all this time? Is it not simply some nostalgia binge which won't survive the first interval? Can people in their 70s hope to make contemporary music for anyone but crusty old fogeys?
Of course, all that ignores one central fact. You only have to listen to classic ABBA to realise Benny and Bjorn are prolific musical geniuses and that Agnetha and Frida are two of the finest voices in 20th-century popular music.
They were never trendy. Trashed as "mere pop" by the devotees of Genesis, Barclay James Harvest and the prog rock era, they were even further critically panned when punk arrived.
Yet it must be said there were nervous sensations in the US and at NME and Sounds in Britain - the gospels of Everything Heavy and Loud - that this ABBA might in fact not only be catchy and engaging, but also, scarily, something subtle and clever as well.
They were right to be nervous. King Crimson was doomed just as surely as the Leighton Buzzards - and it was gorgeous melody and the lyricism of urban isolation that would bury them.
The hits just kept on happening: (Gimme Gimme Gimme) A Man After Midnight, Money, Money, Money, SOS, Does Your Mama Know?
You want more? The life-affirming Dancing Queen, The Winner Takes It All (Ingmar Bergman as a three-minute pop song), the towering if under-appreciated Lay All Your Love On Me, the utterly memorable and haunting The Day Before You Came.
Even at their most raggedly - Ring, Ring, the mariachi schmaltz of Chiquitita and Fernando, the lumpen disco of Summer Night City to give just a few examples - they were miles better than their cultural betters.
In the shoot-out, the macho Anglophone world of punk and New Romantics had the poses and the patter but, alas for them, the Swedes had the bullets. They became universal - young, old, hip, staid - and today they appeal to everyone. No wonder they knitted so well together to make not just one but two mega popular musicals.
Of course, you will still get the craggy old diehards denying any affection for the group, but ... well ... we just don't believe you. There will be doomsayers saying that you can't turn back the clock, that it was all about the times and the context and that a "new" ABBA will be a creatively bankrupt money-making machine.
But I'd still place a fiver on Don't Shut Me Down and I Still Have Faith in You being slices of timeless pop perfection. And that's not a bad start.
Why have they remained popular over nigh on five decades? Apart from the great tunes, you could actually hear what they were singing. Like a brilliant foreign language student, their diction was better than the Anglos - every syllable clear, distinct and, well, unforgettable.
Their songs are packed with everyday English idioms and even when they got the odd one so slightly wrong ("buses I have missed" - I Wonder/Departure), you heard and you believed. It was the language of real life. Once heard, never forgotten.
Never for them, punters saying, "You know that one that goes, 'Something something something/Electric mice under my friends/Something something something/Bombing marshmallows". Oh no.
If bands like The Stones and The Who got older like immature teenagers, and U2 lectured us on how to be right on, and the Spands and Duran Duran were all about style and flash, and Madness and Bronski Beat were all street and unemployed, it was ABBA that described the lives of people like you and me - not as we were then, but as we were all to become.
For a while, they were two couples, married, with children. The songs came to narrate those lives - break-ups, divorces, party aftermaths, loneliness, commuter living, self-help, the reproach and regret of what might have been: "In these old familiar rooms children would play/Now there's only emptiness, nothing to say."
Only the very greatest artists catch the mood of their time when no one else even suspects what it is. In popular music, that's the Beatles, David Bowie, Kate Bush, Sir Freddie, Prince and Madonna. And in there, too, are Benny and Agnetha and Bjorn and Anna-Frid.
With one big difference.
"Paris restaurants./Our last summer./Morning croissants./Living for the day, worries far away./And now you're working in a bank,/The family man, the football fan/And your name is Harry. How dull it seems./Yet you're the hero of my dreams."
Or "You and I can share the silence/Finding comfort together/The way old friends do/And after fights and words of violence/We make up with each other/The way old friends do."
Or "I was sick and tired of everything/When I called you last night from Glasgow./All I do is eat and sleep and sing/Wishing every show was the last show."
Full rhymes, comprehensible sentences, poignancy and astonishingly fertile melody.
Pop trash? You try writing those melodies. And then the lyrics.
Er, in Swedish.