That day, King told Tan he'd been thinking of writing a book about the craft of writing. 'Then I didn't see him for a long time, because he had a terrible accident and spent months recovering'.

When he finally called, it was the day Tan's long-time editor, Faith Sale, died from cancer. She was feeling bereft. 'He said, 'I'm in New York. Would you like to get together?'. And I thought. 'Yes, today that's what I'd most like'.'

At the meeting, King showed her the galley proofs of his book On Writing, which has since become a huge seller. He most wanted her to see the dedication page - which was addressed to her.

'He said I'd given him permission to write it,' she says. 'Of course, I hadn't given anyone permission to write anything, but I felt so honoured. It's the only time anyone has dedicated a book to me. And it was one of those magic moments - it felt like a holy moment.'

Tan's life has been full of such moments, she says. Some years ago, she was with her mother when she died. 'That's holy for me. And at the other end, there are people who see a baby taking its first breath ... That's holy too.'

Although her books are about many other things - she once said she always starts writing a book to answer a specific question in her life - they're also about her understanding of the role that these 'holy moments' play in our lives.

She says her faith, if that's what it is, 'is an ongoing wonder and acceptance that mysterious things happen, and that occasionally in life we get hints about it'.

'Holy to me is about how whatever is out there is greater than we can ever know - that it's more wonderful and horrific than we can ever guess.'

In recent years she has experienced that 'holiness' in all its cruelty - not just with the deaths of her mother and her editor within two weeks of each other, but also contracting Lyme disease in 1999, with its symptoms of insomnia, stiffness, lack of concentration, memory loss and seizures, preceded by moments of extreme and 'almost holy' vividness.

As a storyteller Tam is philosophical about what has happened to her physically. 'If everyone was fine all the time and nobody died, then what would it all mean?'

But she's less detached about what has happened to her virtual self, as found on the internet. 'I first realised it when I needed to put something together for somebody about the awards I'd won.' She couldn't quite remember, so she looked on the internet.

What she found was both amusing and depressing. 'There were rewards and distinctions on there that I'd never received [including the Pulitzer, the National Book Award and even the Nobel], and rewards and distinctions I actually received weren't even listed.'

That was just the beginning. She found that Louis DeMattei (to whom she has been married for more than 30 years) was frequently referred to as her 'current' or 'first' husband, as if she'd had a succession of partners. There were stories about her working in a factory, living it up in the multimillionaire San Francisco suburb of Hillborough (which she once went to for a fund-raiser), teaching poetry in West Virginia (which she has never visited) and having stand-up fights with her editor and her agent - the former most dramatically (and falsely) in a bookshop, with punters dodging the books she was flinging about.

The truth is that she's had one husband, one agent (with whom she has only ever argued about the lunch tab), would have had only one editor had she not died, and has never worked in a factory, although like many students she had a few part-time jobs, including making pizzas and operating a switchboard.

'It was strange to learn about this fictitious person who was me and not me,' she says. It was like being inside one of her own books - particularly her latest, Saving Fish From Drowning, where at times fiction is dressed persuasively as fact, and readers struggle to know what's real and what isn't. Not that Tan usually reads the stories written about her, which may be why the mistakes have gone uncorrected for so long.

'In the beginning, I read the reviews and interviews, but I realised that the good ones made me think, 'Oh how nice', and wonder whether I could make my writing more like what they liked. And the bad ones made me feel physically wounded.' Now, before a book is published, she writes an e-mail to everyone she knows. 'I say, 'I have this book coming out. Please refrain from sending me the reviews, whether they're good or bad. And don't send me a letter saying how terrible you feel at some critic saying they hated it'.'

'I know my writing isn't perfect. I know there are flaws, but I don't need to be beaten down about them. Some people say I'm an ostrich, but I say that writers have to be ostriches. We have to enter a world that, for a while at least, nobody else knows about. And we have to stay there, alone.'

And then, after all the writing, the book is published and the private writer metamorphoses into public speaker. 'I like the quiet aspect of writing, or at least how it's quiet on the outside even if it's turmoil inside. But if I've been writing for 12 hours I'm almost inarticulate'.

Sometimes it seems as if Tan is always saying no to engagements and appearances. But, as she says, if she accepted everything and fulfilled everyone's expectations of what she can do to help their causes, she'd fill up every day and still not be good enough. Nor would she write anything new.

When she's travelling she doesn't write books, but she does keep a journal. 'Sometimes I read it later, and some bits I don't even remember writing, but I think it's interesting and I get pleasure from the ideas all over again.'

Being in China is always good for journal writing, 'because a fluctuating part of me is Chinese, and so it always throws up observations and thoughts'. Those aren't always what other people expect. 'When someone asks are you more Chinese or American? Or more Asian than Chinese? Or ... it goes on and on and on. I never know what to say.'

The first time Tan went to China she thought she'd become more Chinese - and part of her did. 'But the bigger part of me felt more American than I'd ever felt before. I suddenly realised I was very American.'

One of the unexpected implications of having been born to Chinese parents is that Tan has been asked on many occasions to represent the international Chinese community. 'Since I happen to be Chinese there's the idea that I somehow have to have an affinity with the whole of China,' she says.

'And I'm concerned about being labelled a Chinese American writer because it sets up an expectation. Can an Asian-American writer write about football players in France for example? Or can someone in Texas who isn't Asian write about Asian Americans? What does it all mean?'

Some readers tell her they wish her Chinese characters could be role models. What a shame that this character is so troubled, or that her mother character has a strong accent. Can't you make them stronger, better, without accents, so readers will feel better about China and Chinese people?

Tan doesn't do that. 'My books aren't public relations exercises. Some people pander to populist movements but I hope I never will. I'll be criticised for it, but I'll try not to read the criticisms.'

Tan lives in the top two floors of an apartment block in San Francisco, in a home that isn't as palatial as some of the houses she's said to own. She says she has no idea of what she owns, or how much she earns.

'From the beginning I asked my husband and my agent not to tell me numbers,' she says. Knowing might get in the way of her writing. Even when she fills in her tax return, her husband covers up the final number, 'and I sign'.

'I'm pragmatic. I don't expect to ride the wave forever. I've asked my husband to manage things so that when I never sell another book - and I don't mean sell another book to a publisher, I mean sell another book in a store - we don't have to worry. So that we don't have to sell the piano.'

The day ahead is what Tan calls 'an admin day', rather than a writing day. Tasks include talking to a vet about cataract surgery for one of her Yorkshire Terriers and then going to Los Angeles to give a talk at a girls' school. 'It's a favour for a friend because somebody else pulled out.'

All of the girls will have read The Joy Luck Club, she says, with a slight groan. The book has been chosen as one of nine in the National Endowment for the Arts' Big Read this year. 'It's a huge honour,' she says.

Most of the writers are dead, and of the three who are living, one - Harper Lee - is a recluse, and the other - Ray Bradbury - is 86 years old and finds it hard to get around. So the onus is on Tan, who, as ever, is finding other people's expectations hard to live up to. 'I've decided that I'll just do a few appearances, including Denver, because my brother lives there.'

And the inclusion of her book in the list is about to lead to another concession. 'I haven't read [The Joy Luck Club] since I wrote it nearly 20 years ago,' she says. 'Now that I'm going to have to talk about it so much ... well, perhaps I should take another look.'

Saving Fish From Drowning by Amy Tan (Ballantine Books, HK$117)

Amy Tan, Mar 18, 10.30am, Fringe Theatre, HK$250; Mar 20, 7pm, Central Library, HK$160; Mar 21, 5.30pm, China Club, HK$500. See Books pages for more festival coverage