It is Thursday morning, and Craig Shergold strides into the post office in Wallington, England. "Here I am again!" he announces. A postal manager looks up. "I can't get rid of you," he says with a grin.

Shergold smiles, but after 11 years, the joke is wearing a little thin. He is here to pick up this week's mail—23 bags of it—the latest of more than 300 million get-well cards and letters that have poured in from all over the world since he was 9.

The deluge began in 1989, after Shergold was diagnosed with a life-threatening brain tumor. To cheer him up, a friend began a campaign to get Shergold into the Guinness Book of Records for receiving the greatest number of get-well cards. Shergold made the book in 1991, but thanks to chain e-mails, the cards just keep coming. "They come for every occasion," he says. "Christmas. Easter. Valentine's Day. Although I don't mind the Valentines if there are pictures."

The good news, of course, is that Shergold has lived to regret his friend's idea. One letter, in 1990, came from a doctor friend of media mogul John Kluge's. Kluge later paid for lifesaving surgery for the boy at the University of Virginia Medical Center. "If it hadn't started, I wouldn't be here today," says Shergold, who lives at home with his parents, Ernie, 61, a retired truck driver, and Marion, 53, a retired waitress.

Shergold, who is looking for work in computers, admits to being overwhelmed by the mail, which requires 15 volunteers to sort. (He doesn't respond to all the letters but donates the stamps to charity and sends the proceeds from recycling the paper to cancer research.) "It's been great," he says, "but I wish it would stop."