Sarotte is correct: Schabowski had avoided a direct answer to my question. There was no good answer; he repeated the question to give himself time to think, though this only encouraged the viewers to ask themselves the same question. But the logic of the regime's decision to allow its citizens to freely travel and emigrate was clear. There was no point in maintaining a heavily manned and fortified Wall, complete with increasingly deadly automatic weapons systems, dividing not only the capital but the whole of Germany, if people could come and go as they pleased. A Berlin Wall which did not divide the city and the people would have no raison d'être. Yet without the Wall, the German Democratic Republic would lose those people. That is why it had been built — against international agreements — in 1961. The GDR, however, justified the Wall with a lie: that this "anti-fascist protection barrier" existed to prevent a Nazi invasion. The Berlin Wall, the most notorious symbol of the Cold War, was built upon a lie. Even the concrete blocks from which it was constructed were toxic, being full of asbestos. Its model was the Nazi wall that had surrounded the Warsaw Ghetto. The Berlin Wall was the totalitarian lie in concrete form.

The precariousness of that lie, and all the other lies on which the whole existence of this "democratic republic" was predicated, became manifest to the East German people in that pregnant pause when Schabowski was faced with my question. He could not tell them the truth, even though the truth was staring him in the face. And in that moment, the culmination of months of protest, the people lost their fear and the regime lost what remained of its legitimacy. When they went to the checkpoints and demanded to be allowed through, the border guards — who were still under orders to shoot to kill — lost their nerve. Within hours of the press conference, the Wall was open. Young people who had watched the press conference recognised me and embraced me in the street. We celebrated with their home-made wine. Truth had prevailed over lies that proved to be more precarious than anybody had supposed.

How do I feel about it all now, 25 years later? Fortunate to have a footnote in history, especially when the history is written by scholars as distinguished as Professor Sarotte. Happy to have had a walk-on part as one of countless extras in the one modern German drama with a happy, bloodless ending. Above all, I feel proud to have done what journalists are there to do: to make it clear to the world what is happening, to be the voice of the powerless in the presence of the powerful, to ask them the right questions. Sometimes there is no answer, for silence may be the most unintentionally revealing answer of all.

Since the Wall opened that night, the world has opened up too. It is hard for people who can email, text or phone anybody and tell everybody what they think on social media to imagine the world of 1989, when reporting the opening of the Wall meant dialling London for half an hour to get a landline out of East Berlin, dictating my report over the phone to a copytaker and hoping that I had accurately taken down what Schabowski had said, because there were no search engines to check it. Today you can fly almost anywhere, certainly within your own country; but when the Wall came down, even Chancellor Helmut Kohl, who was in Warsaw at the time, could only fly to Berlin to greet the cheering crowds through the air corridor agreed four decades before by the wartime Allies, which meant a lengthy detour via Hamburg.