I first saw U2 in 1978. They played a pretty shambolic gig in Howth Community Centre. They started the show as a five-piece named The Hype, and featured The Edge's brother Dik as a second guitarist.
Dik left the stage - and the band - halfway through, and Bono announced that the re-shaped foursome would from now on be called U2.
Within a year of that chaotic Howth gig, the band played the first of six afternoon shows in Dublin's Dandelion Green - a sprawl of dilapidated dereliction on a corner of St Stephen's Green.
The four school pals had already announced to the world that they were something very different.
The New Wave of music had brought recognition abroad for Dublin outfit The Radiators, and had also helped to deliver chart hits for The Boomtown Rats (featuring Bob Geldof).
But both those bands were a good 10 years older than U2, and they sounded like seasoned pros who had managed to jump a handy bandwagon.
U2, on the other hand, genuinely sounded like they were just making it up as they went along.
By the time of U2's first show at the Dandelion Green, the word was beginning to spread that they were something uncommon.
Those who'd paid the 50 pence admission fee were pretty much the same faces who'd followed U2 by night, from one pokey dive to another pokey dive.
That would change dramatically over the coming weeks, as the few dozen who turned up for the first show swelled with each passing Saturday.
Years later, as U2 conquered the world, the Dandelion Green would become its generation's counterpart of the GPO Easter Rising in 1916, with several million people claiming to have been there.
But what were U2 like on that Saturday in May 1979? Well, for one thing, they looked the part.
Larry Mullen was the pin-up.
Baby-faced he was, but he was already developing the chiselled features to match his rocksteady drumming.
Guitarist The Edge (whose real name is David Evans), with what was then a luxuriant thatch of black hair, was simply a wonder to behold. He so melodic and so different that he was worth the price of admission alone.
Adam Clayton, on the other hand, was already building a reputation as the luckiest bass guitarist in the world. Pushed to the limits of his capabilities, he could just about manage to strum out a useable 'dum-dum-dum-dum'.
And then there was Bono. He looked like a rock star was supposed to look, in his short leather jacket, his skin-tight leather pants, and his pointy Cuban heels.
But he had yet to develop the chocolate-textured singing voice that would make him one of the all-time great stylists.
He sang in a high register, all too often aping the faux-Cockney style of Johnny Rotten.
And yet, he was already developing the intuitive sense of showmanship which would, just six years later, see him hold captive a worldwide audience of millions at Live Aid.
Even a year into their existence under the name U2, the band had a paucity of decent songs.
They would regularly open with around a half-dozen self-penned tunes - only to then close by playing the same songs all over again.
But the songs were always less important than the performance. While it was the punk convention to dash out a flurry of sub-three-minute ditties, U2 were different in that they could riff for 15 minutes on the same tune if they wanted to.
At the first show, Bono's growing improvisational skills were tested to the full when the band's primitive generator broke down, leaving them with no guitar, bass or amplified vocals.
Unfazed, the singer invited one audience member on-stage to hum Adam's bassline and taught another how to sing The Edge's guitar riff.
With U2, even when things didn't go to plan, they somehow went to plan.
But there was a specific plan behind the Saturday afternoon shows at the Dandelion Green - and it worked a treat.
While the first Saturday show was a case of preaching to the converted, the word swiftly spread, and by the last of the six shows, the draughty car park was heaving with a new, young faithful.
At that final show the band added a new element that would become part of the U2 stage ritual, with manager Paul McGuinness handing Bono a bottle of champagne, which the singer sprayed over his newly-won clutch of adoring fans.
Really, you had to be there.