Book Festival - Autobiography and the art of finding links between fact and fiction

There are some readings at the Book Festival that compel attentiveness, that absorb and entrance even the most jaded, tired, end-of-second-week, heard-it-all before festival-goer. This is one of them.

If a dull Galloway reading is almost impossible to imagine, so too is imagining a better one than she delivered on Saturday evening to launch her extraordinary, moving memoir, This Is Not About Me.

Already, she has transformed herself into her domineering sister Cora, preening in front of the mirror preparing for a night out at the Bobby Jones Dance Hall, hair sprayed into submission, make-up applied to perfection, ready for the night ahead and heading out blithely ignoring all her mother's warnings.

But she has also become the wide-eyed four-year-old watching this metamorphosis in the cramped Saltcoats box-room that she shared with Cora and her mother. And she has drawn a no less compelling portrait of her put-upon mother, for whom even this narrowed life was a sanctuary from a worse one with her husband.

Autobiography of this depth and honesty, showing the terrifying confusions of any childhood, let alone one caught between two such differing adults, is rare indeed. Add to that Galloway's ability to talk about her work so lucidly and to read it so perfectly, and you have one of those events where you want the clock to slow down, and that in-tent intentness to linger longer in reality rather than – as it will do – long and deep in the memory.

Autobiography was actually one of the themes of the day. Earlier, reading from his coming-of-age novel Wakening, Derek Johns (who also happens to be Galloway's literary agent) had said it was "in a sense, at the root of all fiction" – a qualification that much of the rest of the day's events teased out.

So among Johns' fellow panellists Susan Irvine could draw on her knowledge of the fashion industry, Kate Muir on growing up in 1970s Scotland and catching the buzz of success in the London media whirl, and Muir's husband, Ben MacIntyre, could eloquently expound on the astonishingly precise links between Ian Fleming's own life and that of his world-famous creation, James Bond.

But it was Margaret Atwood's event that caught the clearest echoes of Galloway's. Before a diverting discussion that incidentally revealed the full extent of her non-writerly knowledge (a childhood that equipped her to mend car engines and sewing machines and an adulthood in which she has invented a robotic book-signing device), she read an unfinished story that she had intended to include in her wonderful collection Moral Disorder.

In it, the narrator writes about books in which her now-dead father, an entomologist who grew up in the wilds of Canada, had written in the margins. She finds a note in one hinting about writing his own autobiography.

But the note ended with that one word, as if he'd despaired that anyone would ever be interested in a remotely distant, seemingly unimportant life. From that unfinished story about an unfinished story to Galloway's achingly moving memoir might seem a huge leap. It's not. Not at all.