Uncertain times have always fostered Cinderella stories, from Dickens's tales of orphans triumphing against the harsh backdrop of the industrial revolution to shop girls transformed into Busby Berkeley showgirls in the Great Depression.
Hollywood sold many variations of the little ol' farm-girl who becomes the glamorous star through the 1920s and 1930s, most notably with Janet Gaynor in the original A Star Is Born.
And David O Selznick's spiritual heir, our great star maker and Svengali Simon Cowell, has revived the tradition, holding out the dream of instant stardom and riches for shop girls and postmen such as Mary Byrne and Matt Cardle.
Mary Byrne, the humble Dub who went from a Ballyfermot supermarket to overnight stardom via The X Factor, helped distract us from hard times when she blazed a trail to last year's semi-final.
And now comes Mary's official autobiography, This Is My Life, (from publishers O'Brien), the "inspiring, funny, heart-warming story of a woman who found fame against the odds".
Byrne's official biography does face the big problem of dealing with a lady whom many of us, whatever the level of attention we pay to The X Factor, might feel we are already thoroughly familiar with. Such is the remorseless publicity generated by the ITV talent contest, it's almost impossible to avoid the overnight and often fleeting celebrities it creates.
Cowell's genius is to take the backstory of the contestants and put it out there in great detail, ensuring that the general public are totally invested in their histories of heartache, family tragedy, and the virtually trademarked "triumph against the odds".
In Byrne, Cowell and his minions found an almost perfect life story. A single mum, working behind a till at Tesco's, belting out karaoke at the weekend, but held back throughout her life by her self-confessed low self-esteem.
The fact that she had a powerful voice, in the great tradition of soul-belters such as Shirley Bassey and the now forgotten Welsh music-hall star Tessie O'Shea (who once took Broadway by storm and shared a bill on The Ed Sullivan Show with The Beatles), made her all the more attractive.
Byrne's weekly, full-throated versions of Shirley Bassey and James Brown songs endeared her to the public and to the Irish, and British newspapers eagerly delved into her life story, turning up old boyfriends, heartbreaks and scandal.
So it's a tribute to a life fully lived that her autobiography does throw up some genuine surprises and succeeds in making the target audience interested in a person they may feel they already know a lot about.
This Is My Life does, in the tradition of modern celebrity biogs, go into every detail from the sometimes difficult childhood (the family were poor, as were many working class families in the 1950s and 1960s) to the disappointments of her later life.
But it is not 'Mary's Ashes'. Byrne had a sense of adventure that must have made her stand out in 1970s working-class Dublin, travelling with a friend across America before her 21st birthday and even spending time living on a Kibbutz in Israel.
She talks frankly about a difficult love life, breaking up with her first serious boyfriend and then embarking on a loving (but as she says, hardly sexually torrid) lesbian relationship with a friend she met while working in a packaging factory in Dublin.
Her ghost-writer, music journalist Eddie Rowley, pulls off that difficult trick for ghosts in keeping his own voice out of the book.
It rings true as Mary's voice - sometimes sentimental, occasionally prosaic, always honest (as far as we can tell. It is, after all, her version).
This Is My Life could have been a shameless exercise in cloying, A Star Is Born fodder, a by-the-numbers Cowell production for instant consumption.
It's a tribute to Rowley and his subject that it offers a good bit more than that, even if it does slip into gushing mode when Mary meets up with Cowell and Louis Walsh and steps on to the celebrity merry-go-round.
However, we can hardly blame Byrne for that. Strip away the spin and it is really an amazing - to employ that much-overused, TV cliché - 'journey'.
It must have been, well, really weird to be at the centre of that X Factor circus for those months, and the book does give a sense of that strangeness (from belting out Neil Diamond songs in a Ballyfermot pub to singing for the man himself at the Aviva Stadium).
This Is My Life does give a sense of the strangeness at the heart of Cowell's alternative reality.
But for the many Mary Byrne fans who will find it in their stockings this Christmas, it does offer a good deal more than that, and is a pleasantly surprising break from the expected. It's not a put-down to say that many mums, aunties and X Factor fans will love it!