'When I recite some of these numbers, it hurts'

Tom Morton spends six hours a day on his numbers. He reckons he must have written out more than 50 miles of them on the small paper rolls stacked on his desk. He learns and revises by day, and drives a taxi at night. In November, he'll sit down in a hotel suite in Blackpool and attempt to break the British record for reciting pi, the infinite mathematical expression. The record stands at 20,013 decimal places. He reckons it'll take him about seven hours.

Tom Morton didn't realise that his memory was different from anybody else's until he was 20. He had dropped out of college in Northern Ireland and didn't have a job or much enthusiasm for anything. He offered a room in his flat to a Chinese man. "Like me, he was a loner. I liked him because he didn't ask any questions. He had all these memory and concentration studies. I flicked through them once and thought that picture associations were a neat idea." A few months later, he started to see how many car number plates he could remember. When he got home, he found that he could write about 130 of them down. He asked his sister to try. Only then did he realise that he might be different.

He started doing turns in clubs as a memory man. He felt as though finding his memory made sense of how he'd been seeing the world. He moved to Blackpool and on to the hotel circuit, beating calculators, writing backwards, memorising packs of cards in under a minute. But he felt he wasn't getting anywhere. To get into the more lucrative after-dinner market and professional cabaret circuit, he needed a record. "It's a bit like going for a job without qualifications. If I can get this record, it could make all the difference; the Guinness Book of Records is the ultimate calling card."

He thought about tackling the world phone-number record. But the Guinness Book of Records insisted that he learn the same phone numbers as the current world record holder - that meant 15,000 Chinese phone numbers, so he settled on pi.

He feels confident about breaking the record now, but a month ago, he was on the point of packing it in. He learnt about 10,000 numbers and found he couldn't absorb any more. So he rethought his technique.

His mistake was trying to remember the whole number as one continuous image. So he created 20 groups of 1,000 numbers. Each group represents a different journey, such as a tour of Belfast or a cycling holiday he took as a child. As he traces a journey, he picks up the numbers along the route.

To remember the numbers, he built up his own numerical alphabet, linking images to about 150 numbers. Numbers one to 10 are standard rhyming associations: one equals gun, two equals shoe, and so on. But then he goes off into his own associations. For a group of numbers, he creates a cartoon in his mind which he places along the route of the journey. For example, the sequence 0478164378 is located at the Pleasure Beach on his tour of Blackpool: 0 is a unicycle, 78 is a Vauxhall Cavalier (the date of its manufacture), 64 is himself, the year of his birth. So he sees a unicycle riding up the Pepsi Max roller-coaster, meeting four Vauxhall Cavaliers, one of which is knocked down by one Tom Morton, leaving three Vauxhall Cavaliers. He tries to make the images as absurd as possible; they make better mnemonics.

Many journeys are drawn from his past: "It's like driving down a road where you witnessed a fatal accident; you try to avoid it. Well, I can't. I have to relive difficult events. When I recite some of these numbers, it hurts. It's emotionally draining. But then, those numbers are the easiest to remember."

By the end of November, Tom Morton will know whether a year's asceticism will have been worth it. He doesn't entertain the idea of failure, or of making a mistake. Or that it's all a waste of time. His memory now defines him. As he says: "I've got a vast imagination and learning these numbers is a way of controlling it. I can't switch off my memory like a television or a radio. I don't really have a choice." That's why he has already got designs on the world record held by Hideaki Tomoyori of Japan. It stands at 40,000 decimal places.