On a particularly rainy day in Germany, marked by foggy talk about the recession everybody now seems to have become used to, something truly astonishing happened: Cologne's historical archive collapsed. Most people thought of a metaphorical collapse when they heard about it (there has been so much talk about the economic crisis that it is almost impossible to escape the endless attempts to understand "the collapse"). But there was nothing metaphorical about the pile of rubble that remained where once the biggest city archive north of the Alps had stood.

Why is this collapse of a 1970s building housing an old archive major news? The building was destroyed by underground work on the extension of the city's Tube. A bulldozer went to work and thousands of years of documents crashed to the ground. Among these were 13th-century manuscripts, about 65,000 vellum-bound books, rare medieval maps and the literary archives of Heinrich Böll and other well-known writers. It had been raining for several days, the ground was damp and the hole quickly filled with water. Some historians spoke of a catastrophe for European historical research. Most locals, however, took it in their stride. "Well, this is Cologne, we are used to all kinds of destruction," said one man, standing in front of one of the many stale-looking buildings that were put up in the 1950s. Alluding to wartime air-raids, he added that he had seen the whole of Cologne flattened. "What is one building compared to a whole city?" he asked.

How easily historians use the term catastrophe and how quickly this man's mind turned to the past. I find this peculiar because Cologne strikes me as a city not overly shaped by its past, at least by German standards. Cologne has made a lot out of its city centre, despite the many pedestrianised streets that catapult their visitors straight back to the West Germany of the 1950s. There is something outdated about them - not because there are no cars, but because they seem to be populated exclusively by old ladies dressed in anoraks with apparently not much else to do other than go shopping or drink weak coffee and have a piece of Sachertorte. But there is more to Cologne than a time trip back to the 1950s, perhaps because it has a big media industry that attracts youngsters (Charlotte Roche, the TV presenter and author of the notorious Wetlands, is based there) and because it has very strong local traditions (a peculiar mix of Carnival, beer brewing and Catholicism).

You can almost feel a change in atmosphere when you leave Cologne and travel south along the Rhine, as I did recently. As soon as you get to the banks of the Rhine and pass the huge cliffs underneath the rock known as the Loreley, you are immersed in German Romanticism. Many still know by heart Heine's poem "The Loreley", which begins: Ich weiss nicht, was soll es bedeuten,/dass ich so traurig bin ("I know not why I am so sad"). Driving down the windy road and looking over the river in the evening light, you would half expect to see a boatman crashing his boat because he was watching a mythical Rhine maiden and not the approaching rocks.

In Berlin, by contrast, you can't walk far without stumbling on history. Many historical sites have now been turned into memorial sites. These artificial versions of the past are very different from the raw, accidental reminders of history you would find if you grew up in West Berlin in the 1980s.

The house my family lived in, for example, had bullet-holes on the outside. In the little courtyard there was engraved a Star of David - it had been owned by a Jewish financier, and the holes were from heavy fighting in the final days of the war. You would play in the attic and find newspapers from the 1940s. On Sunday afternoon walks in the park, you could see over the waters of the Wannsee, watch the East German border guards and hope to see a spy exchange taking place as you passed a checkpoint. At the time, this kind of history was very much part of our daily life. You couldn't get away from it and so it became a natural part of your life - certainly not the material for introspection or fantasy. Now it seems almost as if this relationship has been reversed: there are so many slick memorials that I suspect many people have grown weary of them - or at least ceased to feel the intrigue of looking beyond the memorial and into history.

Sometimes, it feels like that when you look at younger Germans living in Berlin today. Now that the city is officially one of the coolest places in Europe, many have developed a peculiar sense of being German - a form of confidence, or nonchalance at least, about their nationality. Recently, I passed a boutique that was as Berlin-ish as it could be: all independent German designers, a tiny showroom and a snooty owner. In the window, there was a blouse with the German eagle on it. It was slightly altered to make it appear trendy and fresh but it was the same bird you see in the Bundestag and the same that appeared on Deutschmark coins before we switched to the euro. A friend of mine in his late thirties commented that this was "Nationalist fashion". His girlfriend, in her mid-twenties, saw nothing wrong with it. "Come on, we're past that debate, don't you think?" When I suggested it was simply a case of bad taste, I got strange looks from both of them. Apparently, German symbols remain German symbols, whether you like them or not.