Nothing much, is the answer.
When I was a child, I was told that up to midday on 1 April you could play tricks on everyone, and get away with it. This sounded great, but I could never think of any tricks I could get away with.
"What kind of tricks?" I asked.
"Well," said my mother, "for instance, you can tell people that their shoelaces are undone, and when they bend down to have a look, you say `April Fool!' "
Even at the time I suspected that there must be better practical jokes in the world. I tried the shoelace joke on people, and although it occasionally worked neither side got much fun out of it. The trouble was, I could never think of a better one. Putting sugar in the salt? Putting sugar in the petrol? Digging up people's gardens? Telling them that their relatives are dead? Burning their houses down? Telling them that their houses have burnt down? Telling them that eating beef kills you?
I have never done any of these things. Indeed, I have never really moved on from the idea that April Fool's Day was all about telling people their shoelaces were undone. Unfortunately, even this tiny trick has been sabotaged by time - shoe technology has moved on so fast that hardly anyone seems to have shoelaces in their shoes any more, only elastic sides and Velcro fastenings. And saying to people "Hey, your Velcro shoe fastening isn't properly done up!" is less than side-splitting somehow.
Come April Fool's Day I am now reduced to piously hoping that somebody somewhere is playing some good tricks on people or that the Guardian will come up with another gag as good as its famous travel supplement on San Serif.
The one great thing about April Fool's Day is that it hasn't been commercialised. Nobody has ever seen a way of making a quick buck out of April Fool's Day, so it hasn't been taken over by anyone in the way that the card and flower people have changed Mothering Sunday into Mother's Day, or in the way that the wrapping paper industry has taken over Christmas, the way the chocolate industry has claimed Easter for its own or the way St Valentine's Day has been colonised by the news-paper industry, with entire forests being cut down in Finland every year to carry messages from Mugwumps to Duckbill Platypus. Even Guy Fawkes' Day has been taken over by the harmless end of the arms trade, for heaven's sake!
But April Fool's Day stands alone, undefiled, uncommercialised. Maybe it's because it's not religious. It's the religious feasts which seem to attract the hordes of Mammon most. Christmas, Easter, Whitsun, St Valentine's Day even - all have been prised free from the grasp of the Church and taken over as secular and very profitable feast days. Which is only fair, because the Christian Church stole them in the first place, took over the people's winter and springtime celebrations and gave them newfangled names based on the alleged birth and death dates of Jesus, so industry is only doing to the Church what the Church had already done to somebody else.
Not so April Fool's Day. It may be that joke shops do better trade at the end of March than other times of the year, but that's small fry compared to the Christmas shopping spree. April Fool's Day is a gloriously take it or leave it occasion. The only great threat to April Fool's Day is the way people have started behaving madly on other days which are meant to be sane.
The beef scare, for example, was perfect for 1 April. Or the phenomenon of Michael Howard, the man who never does any wrong and never apologises.
Most of what Michael Howard says and does would only make sense on 1 April. Indeed, most of what the entire Government does and says is an elaborate joke, whether they are blaming Labour for the Scott Report or blaming Labour for the beef crisis...
Interesting, that, the way the Tories have started blaming Labour when things go wrong. Could it be, do you suppose, that the Tories are subconsciously so sick of being in power that they have started behaving like an opposition party already?
Is the Tory government a joke in residence?
Do we have something to laugh at on April Fool's Day after all?