Jeanette Winterson is many things: woman, writer, woman writer, prize-winning novelist, OBE, darling of the literary world, lesbian icon, adopted child. She once described herself as “the only true heir to Virginia Woolf”, and has been variously accused of arrogance, absurdity and genius.

Her first, semi-autobiographical novel, Oranges Are Not The Only Fruit, published in 1985, won the Whitbread Award for Best First Novel, was adapted for television by the BBC, and launched her literary career. I would say “the rest is history”, but it’s in fact the personal ‘history’ of Oranges which has most often defined Winterson as a writer. Although the cynical will see this memoir as a cunning marketing strategy to reboot the Winterson brand (plucky Northern upstart with difficult childhood and tyrannically religious mother goes to Oxford, writes prize-winning novel, has tempestuous romances with married women), Why Be Happy is no Oranges 2.0.

The most moving sections deal with her mid-life psychotic episodes and subsequent suicide attempt. Winterson is famous for the story of her childhood and adolescence, a story told many times before. But the parts describing an adult woman on the verge of self-annihilation read differently, urgent and still raw.

Winterson calls her “mad” side a separate person, a “demented creature living inside”, and the story of their eventual reconciliation is incredibly moving. “She may have been a monster, but she was my monster”: Winterson’s remark applies as much to the psychologically damaged parts of herself as to her formidable adoptive mother.

This book could almost be a ‘how-to’ of heart-wrenching. But Winterson knows how to hold back when necessary. “The one good thing about being shut in a coal-hole”, she reflects on her childhood punishments, “is that it prompts reflection”. “Read on its own”, she immediately confesses, “that is an absurd sentence.” Or, following a description of her adoptive mother’s eschatological pronouncements, depression, and conviction that Jeanette is possessed: “our life at home was a bit odd”.

Winterson does tend to over-generalization – “all adopted children blame themselves” – but that’s the kind of writer she has always been: flamboyant, prodigious, gloriously self-involved, liable to go off on one like an embarrassing friend with a favourite rant. Winterson situates her own story within the framework of larger ones – socialism, feminism, Thatcherism – “this is the story of industrialization, and it has a despair in it, and an excitement in it and a brutality in it, and poetry in it, and all of those things are in me.”

Yes, it’s sometimes self-indulgent, but also very, very funny, melodramatic, wry, then deadly serious. So, after a passage that reads like a self-help manual, “what you are pursuing is meaning, a meaningful life”, Winterson performs one of the verbal sleights of hand that have become her signature: “the pursuit isn’t all or nothing – it’s all and nothing. Like all Quest Stories.”

Why Be Happy is a memoir that isn’t interested in remembering, so much as in acknowledging – and revelling in – the fictions of autobiography; a life understood, and constantly recast, in narrative patterns. “I am short, so I like the little guy/underdog stories.”

Make no mistake: this is artful, precisely crafted, almost ludicrously well-written. Winterson describes standing in the yard, after ‘Mrs W’ has discovered her contraband library and set fire to it, watching the books go up in smoke: “‘Fuck it’, I thought, ‘I can write my own’”. Too good to be ‘true’ in the most reductive sense, perhaps, but Winterson’s writing is so seductive that, frankly, who cares?

As she later writes, “It is a true story but” – of course – “it is still a version”. The pun on ‘aversion’ here, fiction as at once turning away from and facing up to real life, is classic Winterson. “I can’t write my own life; never could. Not Oranges. Not now. I would rather go on reading myself as a fiction than as a fact”. The fact is that she does this superbly.