I was saying the other day that The Guardian was once known as the home of misprints, but that as it had shaken off that reputation, we needed a new one. I suggested the Radio Times as a source of misprints and asked for offerings, which of course has led to many kind readers sending me misprints from The Independent, so I'll hold fire on that one for a while ...

But the idea of Aunt Sallys generally is an interesting one, the way in which something can be exceedingly funny to everyone one year and be forgotten the next. One year we think it is hilarious to say "Norway - nul points", and the next we wonder why we ever laughed. Nothing ever stays funny (except perhaps sex, death and other people's misfortunes). Our favourite targets fall out of fashion and are forgotten.

There was a time, not so long ago, when you could get an instant laugh by invoking the name of Group 4. Not any more. We still remember, sort of, that Group 4 became accident-prone for a while and kept losing things and people it was guarding, but it's a distant memory now and too faint to raise a laugh. Historians will have to tell us why we laughed.

Similarly, I can remember my father laughing at comedians on the radio making fun of the groundnut scheme, and Beveridge, and rationing, and nylon stockings. It must be a good many years since anyone got a laugh out of the groundnut scheme, yet the equivalent of the groundnut scheme is always turning up.

In the last week or two, Channel 5 has become an instant laugh object. I can't get Channel 5 and I don't want to, but even I know enough about it to register jokes about it. (Mark you, I can also remember a time when Channel 4 was good for instant laughs, as a symbol of all that was pretentious and avant-garde and unwatchable.)

I have heard comedians in the last few weeks get laughs out of the Spice Girls (I'll scream if I hear the one about Old Spice Girls again) and I have heard the jokes about Dudley Moore coming back to do pantomime in Southampton (I'll scream if I hear the one about "Your movie career! It's behind you!" again) but I wager that unless someone writes down the reasons behind these passing outbreaks of jokes, we may be baffled in 10 years' time as to why anyone should have thought they were funny.

Some targets do last a long time. Quentin Crisp records that when he first arrived in London people were still whispering stories about Oscar Wilde. Well, I can beat that. When I first went to school, people were still making Oscar Wilde jokes.

(I can even remember one. Here it is. Oscar Wilde comes out of prison and checks into a hotel, where he is seen going to his room with one of the hotel's page boys. He is stopped by the hotel manager, who says: "Oh, Mr Wilde - I thought you were going to turn over a new leaf!" "So I am," says Wilde, "but I think I'll just get to the bottom of this page first ..." At the age of 13, when I had never heard of Oscar Wilde and wasn't aware of homosexuality, this joke took some explaining.)

Oscar Wilde had been a butt of jokes in his lifetime, of course, whether at the hands of Gilbert and Sullivan, or Punch, or the music hall, but we are told that jokes about the Royal Family are something new, and that respect has always precluded them being made an Aunt Sally. This may be true in this country, but not elsewhere.

Edward VII, when Prince of Wales, was regarded abroad not as a future monarch but as a lecherous old brute. When he went to Paris, his female companion was not always the woman to whom he was married, and on one of these occasions some French humorist inserted in the French papers an advertisement saying: "Princess Alexandra wishes it to be known that she is the rightful Princess of Wales, and that anyone else trading under that name or carrying out her functions with the Prince of Wales is an impostor and should be treated as such."

One cannot imagine anyone in Victorian England making such a joke. Nowadays people do joke about the Prince of Wales, but in a very different way, and one day we will have to have the jokes about him talking to the flowers explained as well, just as young people today have no idea why we once laughed at the very mention of George Brown being drunk, or the Red Dean, or Sabrina, or the unfinished Sydney Opera House, or Red Robbo, or parking meters, or Mrs Mills, or Andrew Lloyd Webber, or Centre Point, or Brendan Behan, or the Sinclair C-5 ...

Did someone say, or John Major?