Forget street art, it's the old fashioned graffiti that's really interesting

Girl About Town: We've been scrawling on walls for literally millennia, so why are outdoor arts so associated with urban cool?

A picture taken 09 December 2004 shows a woman walking past a depiction of the now famous kiss between Soviet leader Leonid Brezhnev (L) and east German leader Erich Honecker at so-called East Side Gallery, a 1,3 km-long portion of the Berlin wall.

The man from Cologne has a word to describe Berliners: "Selbstbesoffen," he sniffs, which roughly translates as "drunk on yourself". We are currently tipsy on the more traditional intoxicants provided by Radialsystem V in Berlin's Mitte district, but his point still stands. "They think it's like New York in the 80s."

You can tell a city is having a moment, albeit a decade-long moment , when it's lauded as a capital of street art. Critic-curator Emilie Trice calls Berlin "the graffiti Mecca of the urban art world," and sure enough, it's everywhere; on the remnants of the Berlin Wall, of course, but also expensively recreated in the lift of my hotel. You can also tell this moment is soon to pass when the graffiti moves off the city's streets and into the major galleries. The famous Kunsthaus Tacheles squat in Mitte closed for good last month.

Did we ever really debate whether graffiti was art or vandalism? Since Shepard Fairey's image of the US President was on the cover of Time, it all seems but a fevered dream. Like skateboarding, DJ-ing house and collecting imported trainers, street art belongs to that class of activities that mysteriously retains its youth culture association, despite being mainly practised by 40-something dads.

More interesting than Banksy's bank balance, therefore, is the street "art" that never had any artistic pretensions at all. The Tate's current William Klein exhibition includes a photo of a wall in 50s New York, defaced with such humble tags as "Barbara" and "Derek". Berlin also has graffiti of this unsung kind. The couples who attach initialled padlocks to the rails of the Oberbaumbrucke aren't hoping for a bid from Saatchi, they just want the world to know they once existed.

As my other favourite German (he prefers "Bavarian") Werner Herzog pointed out in his film Cave of Forgotten Dreams, humans have had this impulse for millennia. The wall paintings in the Chauvet caves in southern France are more than 30,000 years old ("Tuk Tuk woz ere 4341BC," etc.)

So, sorry Berliners, street art isn't hip and now, it's perennial and very human. Still, if anyone fancies writing in to complain about the defacement of the local community centre - y'know, for old time's sake - please do. I will have your letter framed and sent to the Museum of International Street Art in LA for preservation.