Jeanette Winterson at the Royal Exchange

Going to a Jeanette Winterson reading is like going to a religious rally. Here are the kinds of crowds you don't often see at at a literary reading, people you've never seen before and those you haven't seen for years: a man with a beard comes up to me and says 'Hello! ... Oh dear, you don't recognise me!' and I say, 'Yes, I do, you're X!' (from long ago) and he says, 'No, no, I'm Y!' He's a man I knew in a time even before that, when Jeanette Winterson published Oranges Are Not the Only Fruit. And they're all here, the people who read that book then and have read it since, and this is what the whole thing's about, because this is an event for Winterson's  new book, Why Be Happy When You Could Be Normal? which her publishers call a memoir but which she will tell us is a new 'cover' of the same story.

I turns out that though we are here to hear Carol Ann Duffy discuss the book with her in the 'Carol Ann Duffy and Friends' series of events, this isn't going to happen. Duffy won't be here and Winterson will simply read and talk to us and take questions. The theatre fills up and there's an expectant hush as through the glass beyond the auditorium capsule we see her approach with her minders, and Winterson enters, all in preacher's black with white shirt and a touch of snakeoil saleman's gold on her brogues, and the whole place erupts in a kind of mass relief and excitement of applause. You almost expect her to bow or make the sign of the cross. And there are the acolytes speaking in the Q & A as if the Spirit has moved them: the first person to speak is a girl on the front row, who tells us in a voice trembling with emotion that she comes from Accrington (as Winterson does) and, honestly, it's like a kind of miracle, but she had never heard of Winterson before but this morning she opened the Guardian and read the article about her and it so moved her, so chimed with her own experience, that she came into town and bought Oranges, and - this is the honest truth - she was sitting reading it in Cornerhouse and someone commented to her that this event was on and here she is, and honestly, she feels it's changed her life... And another woman speaks from up in the balcony and says that as a gay writer Oranges simply saved her life... And at the end the applause goes on and on, and the queue for the book signing snakes round and round the Exchange foyer.

It's quite clear to the cynical observer that Winterson's great subject is herself and her own psyche, about which in fact she's quite upfront: so harsh was her upbringing that, she tells us, she had to go under or make herself the hero of her own life. And a hero is certainly how her fans see her, both in the glamorous superhero sense (which is indeed how she depicts herself), but also because by some alchemy of that apparent self-absorption transmuted into fiction, they find themselves spoken to and confirmed and strengthened by her books (or by Oranges at any rate).

I have a few amused quibbles with what we heard of the new book, and from what Winterson read, I think I prefer the fiction version ('Oranges'). She read a passage in which her adoptive mother accuses her of coming from 'the wrong crib', a crib guarded the Devil, and makes fun of the literalness of such a notion. Yet Winterson's depiction of 'Mrs Winterson', which strains for comedy that lots of the audience appreciated but I couldn't, in fact presents her as some kind of devil, which here seems like a mistake but is richly ambiguous in the fiction version.

However, as always, I loved what she said about fiction. That fact that this 'memoir' is in fact just another version rather than the 'truth', because for one thing memory is selective and for another were are all, in life, invented and made up, creating fictions about ourselves the whole time. The fact that the great thing about fiction is its ability to avoid the linear, and that the truth is often best depicted by the non-linear. In illustration she related how this book leaves out 25 years, which her American publishers didn't like: they wanted her to fill in the 25 years for the sake of linearity. But she stuck to her guns because it was the two things each side of those 25 years that were connnected, on the one hand her adoptive mother and the absence of her biological mother  and on the other her discovery of her biological mother. The fact that books can be a sanctuary, and can give you an inner life that can make you strong whatever - something that many people there clearly felt that her books had done for them. The fact that writers need silence and solitude, and that in the age of the internet it's harder than ever for writers to create that essential balance between being out in the world and retiring to that inner space.

Finally, asked about tips for writing, she made it clear that she didn't really feel you can teach writing, because each time you embark on a book you don't really know how to do it, or how it's going to turn out. It's something unseen or dim, a beast that you have to struggle with alone..