I have finally confessed. It was I who tipped the sugared jellies on to the carpet. It wasn't my brother Nigel, who, because of his partial deafness, didn't possess the linguistic skills to protest his innocence; it was me.

My intentions had been honourable, I swear. I tipped them out only because I wanted to share them equally: a green for you, two greens for me. It was only when I saw the storm of sugar settle on the dark blue carpet that I decided to deny all participation in the event.

It's a moral crime that has been on my conscience for nearly 30 years, so it was about time I told my mother the truth. She was shocked. I was, after all, the perfect child. I was the one who sat quietly in my bedroom, reading Five Go to Rilloughby Fair and designing clothes for my Tressy doll. I wasn't like Diane down the road, who told everyone her mother had bought her from the gypsies. I wasn't like the two Janes at primary school, who wouldn't let anyone into their gang unless they said "shit". (I was briefly made a member when I agreed to spell it.)

Outward displays of moral righteousness are rarely indications of the inner person, even though parents like to believe otherwise. This is why most children live permanently in the closet, letting out the less savoury parts of their personalities bit by bit, only when they feel Mum or Dad are psychologically able to bear the burden of their offspring's imperfections.

The torture of my brother is a huge blot on the perfect landscape of my childhood, and three decades have not softened the blow I have finally had the courage to deal to my mother: namely, that her perfect child was a psychopath. Not content with lettingNigel take the blame for the sugared jellies (which resulted in my angry mother confiscating his), I went on to greater and more devious means of punishment.

Nigel was terrified of bath oils. I used to be given at least eight tubes of bath oils every Christmas, along with lemon soaps in packs of three. The oils were ghastly, rubbery things that gradually melted in the bath. Before my brother and I were placedin the tub together, my father would have to scan the joint for bath oils. Only when it was declared oil-free would Nigel agree to have a bath.

What my parents never knew was that I always smuggled a few bath oils in under a towel and then, just when Nigel was at his most content with his rubber duck, I produced one and floated it towards him. His screams were terrifying. As the oil reached his body, I lifted it from the water and burst it over him. He became hysterical. "They're only playing," I heard my mother say.

Repetition was another of his weak spots. After Sunday School each week, my mother would stop at a confectioner's, which was called something like Leatherlands, though I suspect my memory ill serves me on that one. After the Harvest Festival one year, westopped again at Leatherlands, and when she left the car I decided to sing one of the Harvest ditties I had learnt.

"Harvest time is here again / Thanks to God for sun and rain / Harvest time is here again / Give thanks for harvest home."

It was quite a pretty little song. But less so when you had to hear it 200 times. I sang and counted; sang and counted. Over and over. Nigel was banging on the windows of the car. He was sobbing. His eyeballs were bulging. And still the harvest thanks went on. "GIVE THANKS FOR HARVEST HOME! One hundred and eighty nine. HARVEST TIME IS HERE AGAIN ... "

The hell continued at the dining table. During the summer, when we sat with our huge bowls of strawberries, I persuaded Nigel that by far the most enjoyable way to eat these delectable fruits was to stuff them down as fast as you could. He always fell for it. He would cram them into his mouth three at a time and then, when his bowl was empty, agree that it really was a fine way to eat strawberries.

Then he would notice my still-bulging bowl. Picking up a large strawberry, I would take tiny bites, emphasising each with a cry of "Mmm, delicious strawberry, so lovely when you eat them slowly and can taste all the juice ... pity you have none left."

Looking back, I think the torture began as early as the foetus stage. My parents consulted me on a name for the new baby and I insisted I wanted a brother called Angel. Nigel was the closest they could get. Was there, in me, even at the age of two and 10months, a knowledge that every dolt ever destined to walk the face of the planet would be blessed with the name Nigel?

Or did my vengeance have something to do with the fact that Nigel had blond hair, blue eyes and spent a long time in hospital being given presents?

Mysteriously, my brother and I were nevertheless very good friends; we still are. He's a teacher, he has a mortgage, he plays rugby, and has turned out abnormally normal, given his early start in life. I, on the other hand, am barking. Too many green jellies, I think.