Carnival is upon us, a time when noise is not only allowed but obligatory, when pedestrians resolve to at least try to ignore red lights, and urinating in public becomes a touching expression of comradeship. Every social convention is turned upside down. There is even a moment in the carefully choreographed hiatus when the women storm the town hall, seize power and cut off the men's ties. How Freudian can you get?
Since last Thursday, the start of the "crazy days", the streets have been overflowing with jolly bank clerks, cabinet ministers have been performing head stands for the benefit of the cameras, and shopkeepers have covered their stern faces with red paint. Today the partying and the adultery - which tradition and the law dictate is a forgivable sin if committed during carnival - will all come to an end. The edifice of order, smashed to oblivion in five fleeting days, will be rebuilt brick by brick. Just try putting on your washing machine after 10pm tomorrow.
But until the last float in a four-mile procession passes the town hall this afternoon, anarchy reigns. About a million people will teeter along the route, stuffing themselves with Wurst and guzzling litres of the local beer. "Kamelle, Kamelle," shout the children, waiting for the heavens to open up, showering them with chocolate bars and toffee. Cologne's businesses are spending more than DM1bn on "Kamelle" - "sweets" in the Rhenish dialect.
The townsfolk have been bingeing their way to Lent in this manner since 1341. Unlike the rest of Catholic Germany, where the various guises of the religious festival - Karneval, Fastnacht or Fasching - have retained some of their Christian spirit, Cologne has always preferred to go back to its pagan roots. And while other cities along the Rhine have tried to surpass Cologne in vulgarity, none have come close. Dusseldorf, it is true, scored in shock value this year by erecting a pair of giant breasts on a float, but its well-manicured upper class revellers are no match for the plebeian masses that file past Cologne's celebrated cathedral.
"All one can see is workers with filthy overalls, contorted masks and long hair; farmers in dirty costumes, repulsive nuns, and hags in old- fashioned clothes," observed a Bavarian courtier in 1802. "One can perceive, on these masked persons alone, to what depths tastes and education in Cologne have sunk."
The Bavarian's misgivings were shared by the French occupiers, who banned carnival for four years. In 1799, it was allowed again, only to be forbidden by the Prussians who followed in Napoleon's footsteps. It was exactly 175 years ago that the city fathers finally persuaded the Prussian masters to sanction a procession on Rose Monday.
Ever since then, the celebrations have followed the same rules, enforced by a committee of local business leaders. And because of Cologne's history of occupations, there has always been an anti-authoritarian streak in the festivities.
The season begins on 11 November, with organisers devoting 10 weeks of their life to designing costumes and floats, and rehearsing raunchy show- stoppers.
Everything, as you might expect, runs like clockwork. As the procession turns the last corner at four o'clock sharp, the road-sweepers are already poised with their brooms. Within a few hours, the detritus is cleared up, the drunks stagger home and shop assistants wipe away their smiles. Tomorrow, normal service resumes.