It’s not until tomorrow but I’ve already marked April Fool’s Day with a long-running campaign of deception on my husband.

Not that I’ve been having an affair, it’s a little more trivial than that. I simply fooled him into thinking that decaffeinated coffee was real coffee.

His reluctance to drink decaf - “I need something with a kick in the morning,” he says – prompted me to substitute the stuff in our coffee jar for the decaffeinated version. He drank it for a month, without noticing, and on Sunday evening I told him. He felt foolish, but had to admit he hadn’t noticed the difference.

I’ll be on my guard tomorrow, in case he decides to get his own back and mix cat biscuits with my breakfast cereal.

April 1 is a day when you can get away with silly little pranks in the name of the occasion, or ‘celebration’ as it is widely referred. Why anyone wants to celebrate pranks such as stretching cling film across the toilet or super-gluing £1 coins to pedestrian crossings beats me.

I’ve only ever once played an April Fool joke, when I emptied a packet of plain crisps and filled it with cheese and onion, before offering one to my dad.

He hates with a passion anything other than plain, and smelled a rat well before it reached his lips. His reaction was a bit over the top, and at first I thought I’d triggered a major allergy, but he calmed down once I assure him that the crisps had been incinerated and dumped several miles out to sea.

You can’t believe anything you read in the papers on April 1, so if you discover your sleepy, picture-postcard hamlet has been earmarked for a new monster trucks arena, it probably hasn’t. Or maybe you should check it out anyway, because the way planning laws work, it just might be true.

If you forget the date you can easily be duped. I remember being horrified and appalled back in 1980 when the BBC reported that Big Ben was to go digital. Dozens of people protested. The BBC’s Japanese service announced that the clock’s hands would be sold to the first four listeners to contact them – a fisherman in the mid-Atlantic radioed in a bid.

And talking of fish, in many parts of Europe people who have succumbed to an April Fool joke are called poisson d’Avril – April fish – and have a paper fish stuck on their back. This is believed to date back to an early April Fool joke of pinning a fish to someone’s back until the smell grabbed their attention.

I’d play that one on my husband, if his coat didn’t already smell of manure.