Fifteen years ago, Jeremy Atiyah came looking for an old-world Spanish experience. His neighbours craved a Spain that was 'super-moderno'. Today he admits, perhaps they had a point

Mercedes may not have been my kind of girl, in the same sense that Barcelona may not have been my kind of town. "Super-moderno!" she would shriek, at 5am, at the sight of a chrome Cadillac affixed to a discotheque wall in the name of design. Yes, we were in the 1980s. But I had fled to Spain to live the life of a penniless Bohemian. Had I chosen the wrong city?

Mercedes may not have been my kind of girl, in the same sense that Barcelona may not have been my kind of town. "Super-moderno!" she would shriek, at 5am, at the sight of a chrome Cadillac affixed to a discotheque wall in the name of design. Yes, we were in the 1980s. But I had fled to Spain to live the life of a penniless Bohemian. Had I chosen the wrong city?

There were good reasons for Mercedes' addiction to modernity. The Catalans, after all, were still emerging from a fascist twilightland of sexual, linguistic and cultural repression. But then again, I too was emerging from something that seemed almost as bad – a privileged British education. Weren't we all on the rebound? And yet, while I had taken my typewriter to live in a pension in the Gothic quarter, trapped amid smells of frying chips, with cracked-tiled floors, a creaking bedstead and a front-door key as long as my forearm, Mercedes had got into glamorous hairstyles and designer jackets.

"You like that slum?" she used to ask me, with deep mistrust. I told her that I did. And down the road from the Pension Costa, what was more, at a café called the Casa Jose, where the floors were strewn with tissues and prawn shells, I ate daily lunches of chickpea soup followed by meat or fish a la plancha ("on the plate"). This honest fare, I told Mercedes, in triumph, was washed down with wine drunk from the spout of a carafe. Why pay for chrome Cadillacs in your disco when you could have a set menu with characterful old peasants for £1.50?

We really did not mesh. Mercedes showed me the Pedrera, Gaudi's (and her) idea of what a man's home should look like, rippling round a corner on the Passeig de Gracia like a cliff-faced eroded by centuries of dripping water. Its balcony-rails resembled pieces of burnt-out wreckage, or the dissolved residue of an acid attack.

"You see, we are modern people," Mercedes would exclaim, icily, pointing out half-seen towers swirling from the roof. "We are not peasants, as you English think. Am I right or am I wrong?"

I fear she was right. But I didn't want to be wrong. I wanted patatas bravas, funny old Spaniards, olive trees, ancient inscriptions, idle chat, haphazard service and sunshine; not stylish discotheques or designer bars or the Olympic games or modernism or Miró or Gaudi. Which was why, in 1988, I ran away from Barcelona, vowing never to return. Until now, that is. Because here I am again, essentially the same man, wondering what I left behind.

And all I can say so far, is that the hoopla surrounding the 1992 Olympic games has not yet gone away. Checking in at the new-fangled art hotel, on the restored seafront, I arrive to find thousands of Catalans massing here for a Sunday stroll through the Olympic Village. They are predictably proud of this hotel. It is Spain's tallest building. It has been built within a superstructure of naked girders. Inside, it is full of original art. But when I notice that my room costs £100, I yearn for the Pension Costa.

Meanwhile, the first bit of tourism I need to do, is to visit the Sagrada Familia. Catalans measure their lifetimes by the progress of the works on this place. Stepping out of the metro right now, I confess that I am thunderstruck. Beyond the piles of half-cut masonry, an interior to the nave has emerged, with delicate columns leaning like giant rhubarb stalks to a canopied roof. Now I can see how long I have been away.

I set off strolling, but at an anxious speed, through town. Idly walking is a civic duty here. Mercedes used to assure me that the Spanish derived their late-night energy from doing it with friends before dinner. "It is the best time of the day to socialise. You English go to your pubs after dinner. This is wrong. After dinner is a time for dancing, not for talking."

Yes, I think. Dancing. But now the original Ramblas seems to have lost something. I see foreign fast-food outlets everywhere. What I remember as a peep show is now a bank. The performance artists are still there amid the flower-vendors, but looking rather tired. And when I take a closer look at the Catalans, I see what I have always suspected: that they are old-fashioned at heart. In their eyes I see scant evidence of Miró or Gaudi; but plenty, of new apartments and Habitat furniture.

In the glorious Boqueria market, skinned goats' heads with bulging eyeballs are on sale. The salted bacalao looks as raw as the shores of Newfoundland. I remain as calm as a Spaniard while waiting 10 minutes for service behind a hatted lady who is remonstrating with a fruit-vendor. "Last week the oranges were dry," she is exclaiming, "the week before stupendous, the week before sour! Now I just don't know where I am!"

Even as she speaks, I am noticing that the Boqueria's piles of hand-selected fruit would not disgrace the Harrods' food hall. I see plums from Chile, apples from Japan, kiwi fruit from California. This worries me. What is more, all the housewives are totting up their sums in euros.

Walking down to the waterfront I keep catching views of a city that never used to exist. The Barceloneta district I remember as an isolated grid of alleyways and dodgy fish restaurants on the edge of town; now I see tour groups of schoolchildren, exclaiming over Catalan marvels of the 21st century.

Didn't this bit here used to be part of the sea? This bit where lawns and mature palm trees have been planted? Gaudi too seems to be here, in the dismembered handrails and erupting plazas. I step out onto floating bridges to arrive at a super-moderno shopping and cinema complex called Maremagnum which reminds me of Singapore airport.

It is all wonderful. I'm just annoyed that Mercedes has been proven right. And I promptly duck back into the Gothic quarter, in a desperate bid to find my own neighbourhood. But here, instead of quaint old grocers, I pass shops selling lava lamps, dyed fabrics and ethnic kitsch. Inca and Hindu goddesses have replaced chickpeas and lentils. The grocery stores that survive are now run by Pakistani families.

And where is the Casa Jose? Is this it? I am standing in front of a bar decorated with pretentious Art Deco calligraphy, glinting with bottles and seductive lighting. Credit cards are accepted. The set menu is an astronomical £6.

I am almost in a panic by the time I approach the building where I once spent a year of my life. I pass another furniture shop. Surely that never used to be there? Or might it be that I just didn't notice furniture shops in those days? As for the Pension Costa: I am convinced it no longer exists. Then on street level, right next to the Plaza St Jaime, a mere 100 yards from the Gothic cathedral, I notice a herborist which strikes me as new, until I recognise the smell, a mix of camphor and camomile, mingling with the alleyway aromas of frying oil and cats' piss.

This is it. The medieval doorway is open. It is a place Mercedes would never have gone. I creep up broken brick steps and ring on the bell. A clanking and jangling of keys announces the extremely slow approach of an owner who, when he finally gets the door open, seems not to have seen the light of day in decades.

"How much is a room?" I ask. Seven thousand a week, he tells me. He hasn't worked that out in euros yet. But I make it about £3 a night, a slight decrease, in sterling terms, since the 1980s. I check the room, which hasn't changed in 15 years, and realise, with worry, that neither have I. It still strikes me as a very interesting bargain.

"We just have retired people staying here," the old man mumbles. "The ones who can afford it. You want to book the room now?" I think about years long gone, and tell the man that I will let him know as soon as possible.