Can you remember where you were when you first heard "Dancing Queen"? The chances are it was at a wedding reception, or a 40th birthday party; you were probably five. It was probably mixed in the air with the croaking voices of older relatives pouring down on you, as you ran between their fat, pink legs in a church hall. You probably had a fistful of Wotsits in your possession. You were probably wearing a waistcoat. This is where "Dancing Queen" has made its home. ITV specials, Pierce Brosnan, TOTP2, your nan, buffets, desert island discs, Alan Partridge, Peter Kay routines and karaoke machines.

This is wrong. Because "Dancing Queen" is the saddest record ever made.

In order for this exercise to work, I'm going to have to ask you to forget everything you think you know about ABBA. Forget the cheese and the chintz. Forget the Eurovision song contest. Sit back in as close to silent as you can achieve in your current surroundings, and luxuriate on this:

First things first: what a record. In a conversation with THUMP that we stupidly didn't record, the ever-enlightened DJ Harvey once told us he believes "Dancing Queen" is the greatest disco record ever made and it's hard to disagree. It's a song of such high-quality, a song so beloved, it's been nearly entirely ruined by the weight of it legacy. But even then it triumphs. That initial glissando, the endless, breathless, pirouettes in your ears. The tepid beat—barely faster than your heartbeat—the choral whirls and clambering strings. It's perfect. But you already knew that.

The basic point, the important point, here is this: you have spent your entire life believing "Dancing Queen" is a song about a 17 year old girl, dancing. And to a point, it is. Yet, have you ever thought about the song's vantage point?

You are the Dancing Queen, young and sweet, only seventeen

Dancing Queen, feel the beat from the tambourine

You can dance, you can jive, having the time of your life

See that girl, watch that scene, digging the Dancing Queen

Make no mistake. This song is about the dancing queen, but it is most definitely not sung by her. Herein lies the tragedy. Our narrator has realized that she is no longer the Dancing Queen. She is no longer young, no longer sweet, no longer 17. Now, instead, she watches from the bar; the dancefloor a maelstrom of lost faith, memories, and missed opportunities. She was once 17, and as such was totally oblivious that the moment would ever end.

"Dancing Queen" is a song about this end. Or at least, edging ever closer towards it. It is a song that respects the truth that the passing of time only moves in one direction. That the second after the greatest moment of your life, it is as far behind you as it will be forever. Fuck your inner child, fuck 'you're only as young as the woman you feel'. You are young once, it happens, and then the rest is a slow slide towards something both inevitable and unknown. Of course, that's not to say that the slide into adulthood can't be a rich and bountiful experience. For many youth is an uncomfortable project, full of Muse albums and matted pubes, and as such something they are glad to watch it turn to ash over their shoulder. That's fine, I get that. There are, however, a large percentage of people who only make sense when they are young. People who find a home away from home in the shimmering reaches of nightclubs. A lot of cynics would have you believe that nightclubs are only good for trying to pull women, or that those who purport to love them are merely extending some juvenile urge to deny 'the real world'. Sadly, for all their wisdom, the truth is they don't understand the confidence, the place, many people find when they go out—and just how out of place they can feel once those halcyon days are over. As soon as that moment passes—that moment when they were walking on air through the thick, black promise of the night—as soon as the sun starts to come up on the rest of their lives, they are destined to spend forever stewing on what has ended, or simply pretending it hasn't.

To every wrong-side of thirty year-old still stubbing cigarettes out on coffee tables at 6 the next morning, everyone who has ever spent entire evenings listening to their terrible teenage CD collection, every aching back on a premature night-bus home: this one's for you. This is what it's all about. Watching the Dancing Queen flood the floor with light, a floor you used to own but now creaks under other feet. It's a beautiful scene, sure, but also an inescapably sad one. Yes, it sounds happy, but that's the point. The thick melancholy in every piano chord, the unmistakable, immediately singable nature of the chorus are all part of its power. Sometimes when I listen to "Dancing Queen", around the 2:57 mark, I'm sure I can even hear someone scream. This isn't joy. This is agony.

ABBA have been fucking depressing on many other occasions. They basically live-blogged their respective divorces via disco ballads. "Slipping Through My Fingers" captures, with devastating effect, the slow trickle of child ageing away from their parent. "The Day Before You Came" details the oblivious mundane existence that precedes a life-changing encounter. And "S.O.S."—your Aunty Mary's favourite—horrifically masters the point of total disembodiment from somebody you thought you'd spend forever with. Pretty much everything they have ever recorded is imbued with a wistfulness. A constant interplay between pop sensibility and twisted mentality.

Yet for my money, none of their hits come anywhere close to "Dancing Queen" in the longing stakes. It is a song that says the best has been. The best now belongs to somebody else. The best you can now do is watch the best and remember when you were the best. It's a song for the moment when the value of your memories outweigh the value of your ambitions. "Dancing Queen", a song now most commonly preceded by a function DJ slurring the words "get yer dancing shoes on" into a low quality microphone or belted at West End audiences, is in fact a song about watching the party from the other side of the glass, knowing you'll never be on the list again.