Edinburgh Festival 1993: Hello, Garfunkel's, my old friend . . .: Armando Iannucci diagnoses a curious and contagious outbreak of Assembly Rooms Twitch

I've been coming to the Edinburgh Festival since I was a little boy in Glasgow. The first thing I ever saw was a one-man show about Abraham Lincoln. An American actor read the Gettysburg Address, did a few jokes, a few songs. That magic, the sense of discovery, has always epitomised the festival for me. This is where I had the extraordinary experience of first seeing Trestle, Theatre de Complicite and Arnold Brown.

About nine years ago I came here to perform as a student. It was incredibly depressing. I would see these brilliant things, knowing I was in a crap show. There were 50 of us sleeping in a masonic lodge for three weeks with a huge eye staring down at us from the ceiling. It was the biggest audience we had. I'm still trying to exorcise those memories.

I drove up to Edinburgh this year. My car is an extremely old Talbot Horizon which takes 45 minutes to warm up every morning. The fan belt makes an embarrassingly enormous screeching sound. I end up parking in Musselburgh to avoid the meters and have to walk miles to our show at the Assembly Rooms.

I started the festival off badly by revealing in the Independent that I went to Oxford. I lost a lot of credibility, which may explain why people keep standing me up for drinks. For the past 10 days I've been trying to meet Mark Thomas, but we keep getting interrupted by television interviewers in the Assembly Rooms bar. The media have really taken over this year's festival. Every performer has a public relations entourage. A typical day begins with a day-in-the-life-of interview, followed by a quick lunch, then filming something for Edinburgh Nights, and then perhaps another Times profile.

I've discovered that the best place to meet people is actually Garfunkel's around the corner. Nobody involved with the festival will be seen there, so you can slag people off very loudly. Plus they serve huge beef burgers. For the past week I've been living off Garfunkel's beef burgers and Scottish Tablets, which are just compressed demerara sugar in block form. They give you enough energy to get through the day.

Your whole body-clock shifts here. I eat lunch at five instead of one and spend every fourth day trudging around Edinburgh looking for a plastic pint bottle of milk which I need as a prop. After four days the previous plastic pint bottle turns rancid and threatens to explode. My Edinburgh shopping consists of milk and socks. I feel reduced to the bare essentials.

I don't like to eat before a show because I might end up barfing all over the photographers in the front row. Which might be no bad thing. It would give them some great shots.

My partner, Dave Schneider, and I get to the Assembly Rooms at about 9pm and sit in the comedy vestibule. Mark Thomas and Nick Revell are finishing their shows on either side of us. They both do these 'fuck' routines which coincide. You know it's almost time for your show when you get simultaneous 'fucks' from the rooms on either side of you. At about 9.10 Mark comes out looking very sweaty and we arrange to meet for a drink which never happens. Nick finishes at twenty past nine and we go in and set up.

We have a ritual warm-up. Dave does a lot of physical jerks. I sit in a chair and think about my first three lines until I get really bored and pick up the Scotsman. We were reviewed quite early on, so I know I can pick it up and not read another bad review. The Scotsman reviewer suggested that I should stay crouched behind a desk at Broadcasting House. I'm not sure what he meant, but I still want to find out his address and shove a plastic turd through his letter-box. I think he was upset because we weren't like our radio shows. The first week here was spent trying to alter people's expectations of us. Seeing something in print does have an effect. When you open up a newspaper and read 'You are not funny', you want to shrivel up and die. I'm not too worried because I think the sound the audience is making is laughter.

There are certain lines in the show you know are good gauge lines. Depending on the response to that line you can predict how the show will go. But because it's scripted, we can't be too flexible. Three nights ago, before we went on, I caught 15 minutes of a very depressing documentary about Brian Clough. He looked like he was badly made up for a horror movie. His face had exploded into red veins. I was able to work that into the show, since I do impersonations of football teams.

After the show, at about two in the morning, you get into these conversations about the nature of comedy. There's an artificial agenda attached to it each year. Is this the year of stand-up? Of character comedy? It should be about whether the comedy is funny this year. You have these conversations in the Assembly Rooms bar - they started off very silly and are now getting hysterical. Most people develop an Assembly Rooms twitch. You'll be talking to someone and they start glancing at the door. Everybody has an in-built importance detector. It locks on to your face when you walk in the door and measures in about two seconds whether you are important. If not, it homes in on the next person like something out of Terminator.

The highlight of the festival so far was when my mother came from Glasgow for the day. It was great to be a tourist. We hung around by the Princes Street flower clock until five o'clock to watch the cuckoo come out. It was an exquisite performance, beautifully timed. It will run and run.

Assembly Rooms (venue 3), 54 George St, 031-226 2428. 10pm to 4 Sept.

Armando Iannucci was talking to Roberta Mock

(Photograph omitted)