Do you remember the pointless lies you told yourself as a child?

I do. I remember them quite clearly. They were harmless but very powerful and sometimes I almost managed to convince myself that they were true. As far as I can see they served one major purpose: to make life more interesting and more like a story. They were micro-stories.

One that clearly stuck in my mind was almost convincing myself that I'd heard a cuckoo. Of course it was really a wood pigeon, but a cuckoo was more exciting. Cuckoos belonged in fairy tales and clocks, and how much more exciting would it have been to live in a fairy tale?

Or indeed in a clock.

The important thing was not to question it. Of course there was that tiny nagging rational voice at the back of my mind whispering "Pigeon... pigeon... pigeon..." but who was interested in pigeons? Pigeons were commonplace, part of the mundane, the everyday, the here and now. Hearing a pigeon was not anything to get excited about. Hearing a cuckoo - well in my head that was halfway to Narnia.

Sometimes I was nearly successful in convincing myself that the tiny lie was true. There was another occasion that now I remember as almost real. I can see it in my mind's eye. I was about four or five and obsessed with space travel. One morning I looked out of my window and "saw" a satellite. It was a silver sphere covered with long spikes - more like a sea urchin than space hardware - moving along swiftly beneath the solid grey cloud deck that passed for the sky for most of the early 1970s in the UK. I ran downstairs and told my Dad who was standing in the kitchen in his dressing gown making tea. His response was something along the lines of an indulgent "Oh really? That must have been exciting."

The odd thing is I remember so much detail but of course it has to be made up. For one thing no satellites had orbits that took them below the clouds in London N9. No satellites were in the form of giant silver sea-urchins. And for another I can't quite shut that tiny rational voice up.

"Pigeon... pigeon... pigeon..."

I had to have been making it up but the self delusion was so strong in this instance - and has now had so long to bed in - that this imaginary incident looms as large in my memory as many of my real experiences. It is just as valid a part of my background as watching Top Cat on TV, seeing Saturn through a telescope for the first time or the sheer panic I felt when for a few seconds I was convinced that my parents had abandoned me in a department store.

Everything is much more intense as a child anyway. We have yet to learn what our expectations of the world should be and so notice everything around us, sometimes spotting things that adults overlook. To make sense of this brand new complex universe we find ourselves in, our imaginations are supercharged, the Question Machine turned up to eleven. Any books we read and television programmes or films we watch are so much a larger proportion of our experiences than they would be if we'd read or watched them as an adult that it's no wonder the real world often doesn't seem to match up to the potential of our imaginations. There was a police box at the end of our street. One day it vanished, probably removed as part of the Met's program of phasing them out in the early 1970s. I almost convinced myself it had dematerialised. It's understandable that faced with yet another example of the mundane we might try on a more outlandish explanation for size.

But eventually we become adults and the sheer quantity of our experiences in the real world starts to outstrip our supply of more fanciful imaginings. The tiny rational voice is no longer so tiny.

"Pigeon! Pigeon! Pigeon!"

And the small lies we almost managed to convince ourselves were true? They start to get recycled for more sinister purposes. If we're not careful they might start playing a part in getting us to ignore injustice, rationalise our selfishness or justify hatred. I think it's far better that we return them to their original use and every so often entertain ourselves with micro-stories of what the world might only be like if... The rational part of our brains still has a very important part to play - fighting injustice, practicing altruism and battling hatred.