They used to say that everyone remembers where they were when they heard that US president John F Kennedy had died.

But it was 54 years ago this week, so it can no longer apply to anyone under the age of 54. In fact it probably doesn’t apply to anyone under the age of 60 - unless they happened to be a very well-informed toddler.

Perhaps for more recent generations the deaths of Princess Diana or Michael Jackson will hold the same memorability.

Yet even if you weren’t following the news in November 1963 you’ll still have heard of the Kennedy assassination and the mystery that surrounds it.

Switch on the Yesterday channel at random and when it isn’t showing a documentary about Hitler or Henry VIII’s wives you’ll probably find a programme about JFK.

The anniversary fell on Wednesday, yet what I noticed is that the day before it was also memorable because of a shooting in Dallas. It was a shooting in the soap opera of the same name.

The episode on November 21 1980 finally revealed who had shot the central villain, JR Ewing. Around 350 million worldwide tuned in to find out. The fictional shooting attracted almost as much attention as the real one.

And some people can’t tell the difference.

The greatest tragedies of soap operas aren’t just the deaths, the infidelities, the broken relationships, the storylines about domestic violence or alcoholism. They’re the fact that large numbers of people seem to think they’re watching people’s real lives.

When a character dies, viewers send sympathy cards to the relatives. Even christening presents sometimes get sent to newborn soap babies.

When Cindy Beale in EastEnders hired a hitman to shoot her husband Ian, an elderly woman attacked the actress Michelle Collins with her umbrella.

There are people who believe that Anna Friel is a lesbian because her Brookside character Beth Jordache shared a kiss with another female character, Margaret Clemence. By that logic, John Cleese must own a hotel and Frankie Howerd must have been an ancient Roman.

And when Tyrone Dobbs of Coronation Street was getting battered by his wife Kirsty, the actor Alan Halsall found himself receiving letters of support from worried viewers.

His character was not the first on that street to suffer at the hands of a violent spouse. In 1996 Jim McDonald attacked his wife Liz, and pictures of the actress in full bruised and battered make-up were printed in some of the national tabloids.

I was working at another paper in those days and was amazed at how distressed some of my former colleagues were.

Pointing out that this was make-up and Liz hadn’t actually been beaten up, because she didn’t actually exist, didn’t seem to persuade them.

“But still…” one of them said.

But still what, exactly?

And yet all these stupid people have a vote. It goes to show why we shouldn’t put important issues to a referendum, as we’re about to learn to our cost.

I can understand this credulity more with Coronation Street than with other soaps. Dallas , Neighbours and the other American and Australian imports are trashy and improbable, and EastEnders is fairly predictable. Every episode seems to feature someone declaring: “I can’t believe I’m ’earing this.”

But Corrie is usually better written and better acted, and so more believable. And even members of the judiciary watch it.

When William Roache sued The Sun for libel, the judge in the trial more than once referred to him as “Mr Barlow”, so was evidently a fan himself.

Indeed when Ken and Deirdre got married for the first time, the episode received more than 24 million viewers - far higher than the 13.6 million who watched the marriage of Prince William and Kate Middleton on BBC 1. Maybe the Queen should have granted the Barlows the title “Duke and Duchess of Weatherfield”,

And perhaps that’s the test of any good story: whether you end up believing it.

Ken and Deirdre’s daughter Tracy is scheming, dishonest and manipulative, and a work of fiction. For all I know the actress Kate Ford may be a perfectly likeable, good-natured, respectable woman. But I suspect I’d be a bit wary of her if I ever met her.

I first discovered the Greek myths when I was at primary school, and found them to be really enjoyable stories. But the sea god Poseidon always frightened me.

If I'm honest he still does, a little bit.