ONE night about a month ago I sat down to watch The Shining, expecting to be mildly excited by this piece of cinema history and mildly shocked by Jack Nicholson's demonic antics. I'd seen it before, years ago, and remember saying, once or twice: "Oh Jack, stop it, you're scaring me".

But I wasn't prepared for the thrilling moment in the opening scene I'd somehow overlooked the first time. The film begins with an aerial shot of a car meandering through a valley. Nothing remarkable about that - until you suddenly realise that you can see the shadow of the helicopter, carrying the camera crew, on the side of a mountain. Fantastic. I ran around the house with a bugle. There's nothing I like more than a reflection or a microphone in shot, a flaw, a glitch, an incongruity of some sort. Which reminds me ...

Last year I, like most actors in Ireland, had a line in the period drama Moll Flanders. In an attempt to amuse myself and alleviate the boredom on set, I tried to sneak a flaw into the film by wearing a Walkman and a big pair of headphones. But I was caught and sacked immediately, not for the prank but for the shit acting.

And now in my second week idle on the set of The Butcher Boy, I'm up to similar tricks, only this time (because I like tile film) I've settled for a pair of Lycra underpants beneath my 1960s slacks. It's not as obviously anachronistic, but at least I'll have the satisfaction of knowing they're there. I'll have my fun.

I mean, what are you supposed to do when you are clinically bored? (I know I spoke at length last week about this very issue, but nothing has changed in the interim, and besides I don't have a cow to milk.) Anyway, I don't know if any of you have spent much time around actors, but the anecdote comes in handy. The art of spinning out a theatrical anecdote was perfected on film sets while waiting around between takes, and it goes without saying that the older the actor the longer and more implausible the story.

You know those people you meet on the street muttering to themselves? They are old thespians who got lost in the middle of an anecdote. And I know one actor who actually died talking shite. A perfectly healthy man, he was so engrossed in a lie about himself and Olivier that he forgot to breathe.

Even actors run out of names to drop eventually. These gaps in the conversation are filled by overeating. The catering is incredibly good. Somehow or other they can provide hundreds of people with glorious food three times a day from the back of a caravan. Our Lord himself could learn a trick or two from these people.

This display of gluttony is, I suppose, related to the actor's insecurity. It's the "I may never work again so I might as well behave like a camel" syndrome. Actors will tell you they are resting" between jobs. They re not, They're slimming.

THINGS are at last beginning to look up. I've been allocated a "dressing room on the back of a lorry one of those lorries that used to transport racing pigeons if the size of my cubby hole is anything to go by. I try to read but I've got the attention span of a gnat, a gnat with domestic problems. I try to meditate but don't really know how or why? I try to learn foreign languages. I try to write this. I try to sleep, but a strange cooing noise keeps me awake.

I try to prepare for my role. I'm supposed to be playing a dad, the father of the hero's best friend, but I don't have children in real life. (I don't have a real life.) I've no direct experience to draw on. I don't have any acting experience either. What would de Niro do in these circumstances, I ask myself? I pray to him. He tells me I must go out and father loads of children and frown a lot.

This method approach demands that I behave daddishly at all times. So in the preceding days I ignore kids and dance badly at birthday parties. I grow tufts of hair in my ears and spend more time in sheds. I scream and rage and burst veins on the touch line at under 12s matches. I lock children in attics with school textbooks and a jug of water and tell them not to come out until they're geniuses. Now I'm firmly in character. (I suppose the Japanese, bearing in mind their passion for bonsai trees and Lego, must love collecting children - or minature people as they call them.)

Suddenly, just after midnight, there is a knock on the door. It's a frantic person with a walkie talkie. Could this be the moment, two weeks after I arrived, when I finally get to say my lines and expose myself as an imposter? It is indeed.

We shoot the scene very quickly in the end. I expected to do hundreds of takes from thousands of angles and have cocaine fuelled arguments with the director late into the night about my motivation. All I got was a cup of tea and a pat on the back. What an anti climax.

AS SOON as I got back to London, I went to the cinema ... alone. I love going to the cinema on my own. I used to go with my ex girlfriend (now my wife), but she was one of those people who didn't seem to have too much interest in the film itself. She spent the whole two hours elbowing me in the ribs and whispering: "What else was he in?", "What else was she in?", "What else was that car in?" It was infuriating behaviour.

I think from now on, the credits for every movie should not only list the actors' names but should list every other film they were ever in; every marriage they were ever in; every restaurant they were ever in; every biographical detail from the moment they were born, and then maybe I could watch the film in peace.

"Why is Jack Nicholson doing that to his wife?"

"How the hell do I know? You were talking the whole time. And stop hitting me."

We were on the way home on the bus one night. She actually pointed at the driver and whispered: "What other bus does your man drive?"

Anyway, here I am now, sitting in the cinema munching a big sandwich thinking to myself: "Ah yes, it's good to be back in the real world!"

Continues next week