The world changed on Freiheit Nacht (Freedom Night), 9 November 1989, when the crumbling East German state removed the vicious travel restrictions to the West that had kept the people prisoners of their ideology for 28 years. The announcement was buried in the news bulletin after an item respectfully heralding the Fourth Party Conference of the ruling SED - Socialist Unity Party of Germany.
Considering that the child christened Freedom was seven years old last Saturday, there was little by way of birthday celebrations. Indeed, the child is by now unwanted - at least by some. "It would be better if we were still separate," a Wessi (West Berliner) told me. "We are tired of paying for all the mistakes of Communism."
"It would be better if we were still separate," an Ossi insisted. "We had safe jobs, cheap housing and good hospitals." This week, unemployment in Germany hit four million.
As a study in how humanity so readily adapts to new circumstances, Berlin is prime research material. While the city at the heart of Europe recovers from its bypass operation, you must expect some surprises. Walking north along Friedrichstrasse, just as I had done early in 1989, you find the way blocked - just as in 1989. This time, the obstruction isn't because you are approaching the door between two worlds. It is because someone is building the Checkpoint Charlie Business Centre on the grave of the DDR.
So you have to take a wide detour, across what was no-man's-land, before getting into step again on Friedrichstrasse. But at least the labourers don't take DM25 from you, fill your passport with an obliteration of arcane Gothic characters and - in a cold, heavy sweat - make you believe you have transgressed various articles of the East German Constitution. No: they carry on building.
The wound that the wall created is being painstakingly stitched back together. Accordingly, the latest tourist attraction is the biggest building site in Europe.
In Berlin, the Info Box is not the travel information section at the end of this story; it is a bright red cube on stilts that presides like a conductor over the massed ranks of tower cranes busily building their Potsdamer Platz.
While the cranes duck and delve into the foundations of Berlin, visitors to the Info Box may take a trip through four dimensions. Three physical dimensions are created by a succession of virtual reality screens which take you down the time line to 31 December 1999 - when the Sony Centre at the heart of the new development is due to open. As this electronic magic carpet whizzes you around, from the Filmhaus to the Mediathek, you begin to see its resonances between the vast, intimidating, canopied hall of the new venture and the architecture of the Third Reich.
Much of the administrative infrastructure that enabled Adolf Hitler's regime to terrorise the world has vanished beneath Allied bombs or German bulldozers. The Fuhrer's bunker lies beneath a car park, with footballing youngsters unaware of the horrors that were perpetrated beneath their nimble feet. The headquarters of the Gestapo and SS survived the war, but were flattened shortly afterwards - though only as far as the ground floor. The foundations, and the dungeons where victims of the secret police were tortured, have survived. Some of these ruins lie exposed in the Prinz- Albrecht-Terrain, named after the Prussian prince who built a palace on the site, later commandeered by the SS. Nowadays this blank space seems a peculiarly rural flourish so close to the heart of a modern, brash city. But what decent building could possibly be constructed on the territory of terror?
About the only possible answer is the diminutive hut that now occupies one corner of this forlorn field. The Topography of Terror is an exhibition hall: here, the horrors invoked by Heinrich Himmler and his fellow "armchair killers", plus the Gestapo who took a viciously hands-on approach to their victims, are portrayed by silent testimony of unemotional words and grainy pictures, set against the unforgiving prison walls.
Berliners are confronted constantly by their past. Up to 1945, millions were killed by a programme of Fascism directed from Berlin. After 1945, the city was divided by the conquering powers who then fought their proxy battles in the negotiating chamber, where frontiers were carved arbitrarily through communities, streets and lives.
Just as the whole of Germany was split into American, British, French and Soviet sectors, so Berlin was drawn and quartered on military maps. The Western powers lumped their zones together and built a glossy new city from the ashes - though well away from the original centre (imagine a divided London re-establishing itself around the Brent Cross area, and you get the idea. Not much in the way of tourist attractions, but plenty of space for shiny shops). The East became Berlin, Hauptstadt der DDR - capital of the German Democratic Republic. Ossified (no pun intended) for 40 years, it was Middle Europe's most atmospheric city - because, and in spite of, the ludicrous bureaucracy you had to tangle with before being begrudgingly admitted.
One effect of what was cynically termed the anti-Fascist protection barrier was to keep the heart of Europe in suspended animation. The trick the people have accomplished is to breathe new life into the old city, while stopping short of killing it with capitalism.
Now, you can amble through the mix of heroic and horrid architecture. Every now and again you catch a whiff of harsh tobacco smoke and rougher schnapps from a cafe doorway, and are reassured that if the person opposite wants to shop in the Kurfurstendamm, all she need do is keep walking straight through the Brandenburg Gate.
Not that many people these days care to venture to West Berlin's main shopping street. It seems bland, almost tawdry, compared with the grace of the avenues in the East. Unter den Linden, the main thoroughfare leads one way to Paris, and the other to Moscow, and has picked up affectations of scale from both.
Ranged along this boulevard are masterpieces like the state opera house and the cathedral - plus a risible relic of communism. Not the gigantic bronze statue of Karl Marx and Friedrich Engels - though the comic duo look alarmingly pleased with themselves as they survey the surroundings - but the ludicrous Television Tower, a needle sticking into space which resembles something you might find in an over-the-top cocktail. The bulge near the top is not maraschino cherry, but a cafe designed to permit East Germans to peer down upon their erstwhile fellow citizens in the West. Nowadays it just looks silly and vulnerable. Perhaps a new use will be found for it, in the way that other oddments of a tortuous civic history have been adapted.
Take the Deutsche Dom, (German Cathedral), that marks the centre of the 19th-century city. Like much in Berlin, it was devastated by Allied bombing in 1945. The cathedral has just reopened as a civic museum, tracing the often terrible history of Berlin over the past 150 years. Visitors and residents step into a cylinder of history that wraps itself around the coarse red-brick interior of the church in a virtuous spiral. The twisted roots of fascism are on permanent show - confronting the past just as the Info Box lets you look into the future at Potsdamer Platz. The crowning moment of the exhibition is simple: two television sets, replaying endlessly the bulletins of 9 November 1989. On the Eastern set, a po-faced sermon gives no acknowledgement that the world has just turned upside down. Meanwhile, on the Western screen, the ARD newsreader cannot conceal his delight as he does his stumbling best to read the autocue as a broad smile keeps encroaching, with the unmistakable subliminal message that "As soon as I've finished my shift, I'm off to join the party at the Brandenburg Gate."
Tonight, though, they're not going to party like it's 1989. A trawl through the listings of Zitty magazine, between the columns of Luste & Liebe and Fetische-Fantasy classifieds, revealed a paucity of celebration. The seven- year itch was being scratched only at the Volksbuhne, a triumphant emporium on Rosa-Luxemburg Platz. All the trendy things from East and West meet here, either in the Red or the Green salon. Each venue is comfortably retro - an easy enough image to maintain when all your soft furnishings are made in the DDR and therefore look as though they came from the Co- op, circa 1960.
Here you are on the fringe of the Prenzlauer Berg, the antidote to numerous Soviet incursions on the fabric of the city. Prim 19th-century tenements look as tidily bourgeois as ever they did, while the street level has witnessed an explosion of chic cafes. In a decade, this neighbourhood will help Berlin reach the top of the league of genteel decadence once again.
Vitality is being breathed back into the synagogues, too. Prenzlauer Berg was the core of the Jewish community until the dreadful Kristallnacht on 9 November 1938, when 23 synagogues were wrecked by the Nazis, along with countless Jewish properties. The old Jewish cemetery and new synagogue are now slowly being restored.
At last, I shall mention it: the Wall. The casual weekend visitor to Berlin need never know it ever existed, so effective has been the civic surgery. Almost every concrete inch of the 103-mile wall has been removed, sold off to souvenir hunters or reduced to rubble to build foundations for a new city. Only in a subdued suburb a few miles north of the Brandenburg Gate has Die Mauer - the most notorious symbol of the cold war - been remembered. The Mauerpark is a gentle swathe of green that nuzzles against the still-graffiti-strewn section of wall. Here no-man's-land has become everyone's playground. Giant, grown-up swings allow you to rise high enough to see over the wall and to reconcile the two halves of the city beneath a sky full of benign stars. As you swing ever higher, simple harmonic motion replaces the weariness with a sense of joyful liberation. As each swoop lifts you still higher, you feel like an extra in the next Wim Wenders film.
I know what to call it, too: Swings of Desire.
Getting there: KLM (0181-750 9000) is offering a fare of pounds 141.80 including tax, travelling from airports in the London area via Amsterdam to Tegel airport in Berlin. Flights from other UK airports are available for slightly higher fares.
Getting around: On Berlin's excellent public transport system the basic fare is DM 3.90 (pounds 1.60), allowing two hours of travel on the S-bahn (suburban railway), U-bahn (Underground railway), buses and trams. The Welcome Card (24 hours of unlimited travel and discounts on attractions) costs DM 16 (pounds 6.40). Better still is the DM 20 (pounds 8) family card, allowing 24 hours of travel for two adults and up to three children.
Getting advice: The German National Tourist Office's UK bureau is at 65 Curzon Street, London W1Y 8NE (0171-493 0080), but it opens only 12 noon to 5pm, Monday-Friday. You can order brochures on a premium-rate number, 0891 600102.
The Odyssey Illustrated Guide to Berlin by Gordon McLachlan (pounds 11.95) is a well-researched and entertaining guide.Reuse content