I once knew a woman who believed herself to be very grand. "The only time I ever really see ordinary people is when I go to the supermarket," she said. I looked at her. She was wearing leisurewear. Expensive leisurewear, true, but still the stuff that stretches. I tried to imagine the scene as she waltzed round Tesco. Since she was only famous in a rather exclusive way - ie in her own mind - I'm not sure anyone would have noticed.

This not the case with real celebrities, of course, but I'm not sure that A-list celebrities actually go to supermarkets. Years ago a newspaper I worked for ran a series called "Touched by Greatness" in which readers revealed their brushes with fame. It was a huge hit. Everyone who was anyone, it seemed, had run into Kurt (Douglas) or Rob (Redford) over the nasal spray or while checking their car's tyre pressure. But none of the encounters took place in supermarkets and I now realise why. It is hard to imagine Kurt or Robert possessing loyalty cards.

This is not the same for B-list celebs who can often be seen in London supermarkets in search of a photo opportunity. But those of us who shop outside the M25 miss this. I did once spot Kenneth Baker and his pin-striped slime trail at a petrol station convenience store. Does that count? Can a politician be a celebrity? I have also seen Cindy Crawford pushing a trolley but that was in Hello! It must be said that she did look rather ordinary. Perhaps it is the flourescent lights that make famous people look ordinary and vice versa.

Think about it. Ever since that Superstore docu-soap started, people in my supermarket are starting to act up. A week ago one man went into full flounce when his wife suggested they might try tuna instead of salmon. "No, no, no, no," he emoted, eyebrows gyrating. Over in fruit and veg one woman was doing a dramatic (dare I say Shakespearean) ripe tomato test. Equity beware!

Then, last weekend, I saw a couple kissing in front of the bananas. I looked round for the camera. Screen test? She murmured in full stage whisper. "I'm just off now. Can you handle the rest? We need some of that nice herb bread." He looked panic-stricken. "Where is that!" he cried. She pointed and finally lead him to the shelf. They said goodbye again (more kisses). And then, with one last finger flick over the bananas, she was gone. He shuffled over to the speciality soups. I felt like shouting "Cut! It's a wrap!" but decided this couple, like my very grand aquaintance, may not realise just how famous they really are.