A man walks past stands for balloons installed along the former Berlin Wall location, which was used in the installation Lichtgrenze (Border of Light) in Berlin on Tuesday. (Reuters)

This Sunday, it will be 25 years since the fall of the Berlin Wall and the collapse of communism in East Germany. Roger Boyes, the Berlin correspondent of The Times, London, recalls how he witnessed the beginning of a revolution

It was the big communist jamboree of 1973, the World Youth Festival, that first brought me into contact with a society that while vaguely committed to taking over the globe was more interested in looking good and getting laid. Buy a new pair of Levi’s and put them on before passing through Checkpoint Charlie, I was advised by western friends. Take your old jeans in your rucksack, sell the new ones, then put on the old pair. It didn’t seem very complicated.

What I didn’t understand is why I should be conducting an illegal deal with a view to getting unspendable East German marks. Fool, said my friends, the point isn’t to make money but to come into contact with East German girls, who would use Levi’s to buy western cosmetics.

So why didn’t I just smuggle in cosmetics? Because you will get arrested. Aha.

The plan worked after a fashion. I was invited to a party in a dilapidated corner of east Berlin. There were no drugs, just beer and schnapps, and a cheer went up when a friend came in with a smuggled album of Suzi Quatro, the rock star. The women from the Free German Youth — billed in the West as a kind of Hitler Youth lite — unbuttoned their blouses and danced. Later some of them disappeared into rooms with exotic Cuban delegates.

A significant number of young East Germans gave birth in 1974. As I recall I had a snog too but nothing passionate enough to justify the opening of a file by Stasi, the repressive secret police. That came later.

Years later, it dawned on me that I’d witnessed the beginnings of the East German sexual revolution.

“In a rigid state that wanted to control everything,” Kurt Starke, an eastern German expert on sexual sociology, says, “citizens were more emancipated with respect to their sex life, women in particular.”

More women entered the professions than in the West. Divorce was easier, so was abortion, and while 1973 may be remembered in the West for the retreat from Vietnam and the Watergate scandal, in Poland it is noted as the time when, to the dismay of their Catholic mothers, girls could get the contraceptive pill.

Perhaps this was another bit of state intrusion, of social engineering. Chiefly, though, it was an early marker that communist societies were facing a demographic bulge, a new generation, and that an ideology invented and refined by old men had to take this into account.

In the end, the ideology withered and at least some of the young people of 1973 joined, 16 years later, the Leipzig demonstrations that demanded an overhaul of the system. Plenty of reasons are offered for the fall of the Berlin Wall and the collapse of communist rule across the region. The economists said the whole system was basically a Ponzi scheme destined to implode. The religious regarded it as a miracle, the fulfilment of a prophecy. Social historians said it was people power. I reckon it was the sex, the lies and the rock and roll. The monitoring of sex lives was a fixed part of the secret police routine; the assumption being that deep intrusion into private lives, the discovery of weakness, was the way of holding the doomed state together.

My Polish secret police file starts in 1978 when I was a reporter visiting Warsaw and they launched a honey trap against me, using a girl to divert me for the two hours that it took four agents to dismantle my luggage and hotel room.

The declared task of the file (fed in due course by Stasi observations) was to establish whether I was a spy or just an irritating hack. By the time the file is closed in 1989, a few hundred pages later, the case officer didn’t seem sure. Not about the spying bit anyway. He gives me a good concluding character reference (calm, modest, photographic memory) and adds, as if to confirm the consistency of the police’s prurient interest: “The target has a robust sexual life bordering on the deviant.” Plainly something that will have to figure in my LinkedIn profile.

The deviance was, of course, largely on the part of the watchers who dug relentlessly into my personal life.

The Lives of Others is such a good film because its main watcher, played by Ulrich Muhe, performs a moral act by attempting to interfere in the relationship that he’s been observing. The film angered Stasi victims because it made it seem as if secret policemen acted out of conscience. The film’s point though was different: to show that the real tipping point for East Germany, what really crashed through the Wall, was the overpowering indignation that the secret police was trying to burrow into the private sphere and claim it as its own.

The Stasi under its suave chief Markus Wolf cynically presented itself as a force for modernisation, the true voice of Mikhail Gorbachev’s reform socialism and a friend of the East German people. In fact, the secret police were the most totalitarian feature of East Germany, determined to insert itself into the heart of the family. Its “Romeo” agents were trained to seduce women from the typing pool of western defence ministries. Simulated love was an accepted method of infiltrating Nato and saving the East from nuclear destruction.

The resolve to pull down the Wall came at a price. Unlike the rest of Eastern Europe, the East Germans lost their statehood, their specialness. The novelist Jana Hensel, 13 when the Wall came down, recalls wistfully: “Nothing is left of our childhood and all of a sudden, now that we are adult and it seems almost too late, I notice all the lost memories.”

It’s not that anyone really wants their state back. The Wall was an extraordinary symbol of cruelty; it was also a notably bad way of running an economy. Communism may have narrowed income gaps but it also impoverished society.

Yet there also exists a hankering not only for a lost childhood, but for an elusive sense of community that only seemed to flourish when the Wall was standing. “We fought hard for our little private freedoms and we don’t like it now when this is shrugged off by westerners who have simply inherited their liberty,” one historian told me. He teaches in Bavaria now and loathes the smugness of his pupils.

In the western worldview, the East was simply uniformly grey. “Commies love concrete,” proclaimed the satirist P.J. O’Rourke after an exhaustive reporting safari — oh, three, four days at least — behind the Iron Curtain. “Everything is made of it,” he decided. “Streets, buildings, doors, walls, roofs, benches, plus some of the food.”

Yet that’s not quite how it seemed if you lived behind the Iron Curtain. It wasn’t all grey and it certainly wasn’t North Korea. Allotment gardeners in Brno started to talk politics with each other after long years of silence. In Bucharest you bought a dog as a pretext for chatting freely with like-minded chums in the park, away from Securitate microphones.

A nudists’ association on the East German Baltic coast that met under the guise of being a solidarity group with an African socialist state chucked a local party official into the water when he tried to interrupt proceedings. Nobody is quite as resolute in the protection of his or her rights as an East German naturist.

You would have had to have lived in a padded cell or have an enduring child-like fear of capitalist bogeymen to retain a faith in communism. As it happens, I knew one true believer quite well: my Polish father-in-law Zygmunt, who for the first six months of my marriage refused to have me in his apartment in the absolute certainty that I was a CIA agent. In all those tricky moments of communist history, he stayed firmly with the Party. I was the ultimate challenge, an emissary of monopoly capitalism on his doorstep, impregnating his daughter.

“Reagan!” he would say after I was eventually allowed into his home. “A clown! A cowboy! A trigger-happy idiot!” He would then retire to his room to watch Polish state news, which was read out in those days by an announcer in uniform. My wife and I would listen to the BBC in our bedroom. Sometimes he would turn up the volume and we’d reply in kind.

Those dinosaur-believers weren’t the reason why communism staggered on for quite so long. Rather it was a sense that living alongside rather than inside the system was quite stimulating. The former East German dissident Lutz Rathenow expresses it well: “You could live very happily in spite of the system; live against it, awake. It was simply fun.” Jacek Kuron, the late Polish dissident, used to say: ‘Live life in awareness of the secret police but freely, as if they didn’t exist.”

Ordinary citizens, that is those who steered clear of epic battles with the authorities, had a different rationale. It helped, of course, if you had access to dollars, but they found pleasure everywhere. They made time for friendship; the dacha, the ramshackle country house, became a retreat from the state, where one could let off steam. After a while, living in Moscow and Warsaw, popping in and out of East Berlin, Prague and Balkan cities, I became aware of the undercurrents, the ways in which frustrated societies tried to express their individuality.

It was the subcutaneous that made life tolerable, that paradoxically made change inevitable and which 25 years on contributes to the odd yearning not for socialism, but for the alternative communities that it spawned.

What do you remember most vividly of those days, I asked a group of old friends in Warsaw the other day. Well, obviously it was prison if you had been nicked. The beating if you had been beaten.

Chiefly though it was private-public moments such as parties celebrating the name days of saints. Anyone in Poland called Andrew, Christopher, James, Paul and Peter (believe me, the list is much longer) threw open house parties, supposedly in honour of the saint they were named after, but in fact to reaffirm their extraordinary social network.

Under martial law in the early 1980s, these parties enjoyed the advantage of being both spontaneous and not requiring a preliminary phone call. In those days, every call was prefaced with an automatic message announcing, Rozmowa kontrolowana: this conversation is being monitored.

The best, which consolidated the host’s close family with friends, work colleagues and acquaintances, turned into a kind of souk, trading gossip and favours.

Eavesdropping on one conversation I realised how late-socialism had turned casual encounters into transactions. It went something like this:

Matronly journalist: So you work in the Neurology Institute? Fascinating.

Bespectacled doctor: So-so.

Matron: You wouldn’t be a psychiatrist, would you?

Doc: Yes. I treat alcoholics.

Matron: Not my problem. Not yet anyway. Ha ha.

Doc: So what’s your problem?

Matron: I have a son due to go into the military.

Doc: I understand (scribbles phone number). I run a private practice on Thursday.

Decoded: the woman wanted a medical exemption from army service for her teenage son and was willing to pay for it. There have never been so many faux schizophrenics as in Poland in the 1980s.

Orthodox chroniclers of the downfall of communism would point to this as an example of systemic corruption. Yet many of these trades were motivated by familial and social solidarity; they were acts of conscience or at the very least kindness.

Corrupt? Yes, I suppose it was, but even the crudest exchanges can have a redeeming, altruistic quality. My own value — single, British passport — became clear in the Stygian gloom of martial law Poland when a colleague at The New York Times asked whether I was interested in marrying an actress friend to get her out of the country. Had I done so, I would probably still be calling in free theatre tickets.

THE TIMES, LONDON