I gatecrashed a party for young people – and have never been less welcome | Zoe Williams

The host was on to me and my friends as fast as a security guard trying to get a chaotic drunk out of McDonald's

So the scene was a set of railway arches, and there was a different party in each one. In retrospect, it was really easy to tell them apart: it went Weird People, Old People (40+), Young People (-30). But when you first arrive at a venue, it's a bit discombobulating: too much sensory stimulation, very little signposting. It's a reasonable human imperative, I think, to move towards the visible bar, rather than stop to notice that every arch has a bar.

This is how I and a group of friends and family ended up fleetingly in the Young People party on our way to the Old People one. My brother-in-law has form; only last week he was refused entry at a rave because he had no ID, and was last seen taking his bike helmet off, yelling: My bald head is my ID!" I only know that because I was there, inside the rave, and we can deal with what the hell I was doing at a rave another time.

Zoe Williams is a Guardian columnist