When American writer Kate Bolick was in her mid-twenties, she and her boyfriend used to go running after work, jogging through Boston in the early evening. One night, they passed a woman running behind her toddler in an all-terrain buggy. Her boyfriend smiled and said: "Look: there's you some day."
Bolick's stomach lurched, in a scene reminiscent of a Woody Allen film: the career woman horrified by smug maternity, the doltish boyfriend who thinks she is longing for marriage and a baby. "There was no way I was going to become that woman," she thought, "but I didn't know how to say it."
Bolick - who made her name questioning modern notions of romance, family, career and success in 2011 with All the Single Ladies, an essay in the respected American journal The Atlantic - recalls that night in her latest memoir-cum-manifesto, Spinster: Making a Life of One's Own, published this week in the United States.
The title is deliberately provocative. As Bolick writes in her introduction: "The single woman has always been stigmatised as a lonely old spinster with too many cats."
Her remedy is to give spinsterhood a radical facelift - as a desirable, even enviable state. It is a battle cry that is already being taken up on both sides of the Atlantic.
Bolick challenges the idea that women must find a partner, that to remain single is lonely, sad and pitiable. In her beautifully written and passionately argued book, she charts her conversion from romantic teenager to sceptical fortysomething.
If at first she is "bothered" by the idea that a woman must be desperate for marriage, she later finds "the fixedness of this belief not merely claustrophobic and repetitive, but downright pernicious". To counter it, Bolick coins the phrase "the spinster wish": her shorthand for the novel pleasure of being alone.
Drawing inspiration from her literary heroines - which include 19th century American writers Edith Wharton and Charlotte Perkins Gilman - Bolick's book captures the mood of the moment. After Ally McBeal, Sex and the City and Bridget Jones - the spinster singletons of the Nineties and Noughties - today's young women have no desire to be defined by whether they have a boyfriend, don't have a boyfriend, or have persuaded said boyfriend to marry them.
And we are set for a season of cinematic spinsters. Nicole Kidman will star in Queen of the Desert, a biopic about Gertrude Bell, the explorer who travelled 20,000 miles by camel to map the Arabian desert and who helped draw the boundaries of modern Iraq.
Then in October, there is Suffragette, starring Meryl Streep and Helena Bonham Carter with Nathalie Press as the unmarried Emily Wilding Davies, who threw herself under the King's horse at the 1913 Derby.
But opening next month is Far From the Madding Crowd, based on Thomas Hardy's epic pastoral in which Carey Mulligan plays Bathsheba Everdene, the headstrong and independent farmer who inherits a holding from her uncle. In the trailer, we see her confidently telling the workers: "From now on you will have a mistress, not a master." You might argue that Bathsheba ends up with three adoring suitors, which isn't very spinster. But Bolick counters that she offers "spinster" as a blueprint for independence, whether a woman is single or coupled.
She tells me: "Of course, the classic spinster is never married. But I think that her mindset - one of self-reliance, of standing outside the social order - supersedes her relationship status."
Edinburgh-based designer Victoria Fifield, 34, considers herself part of this new generation. "With small interruptions here and there, I am single," says Fifield. "I place a great deal of value on the freedom it gives me."
Keen to reclaim the word "spinster", she calls herself a "hipster spinster": "I'd always wanted to start a band with the name because I like the connotations of spinning records," she says.
Fifield recently struck up a conversation with an older customer, who told her how pejorative the "spinster" term had been in her youth - and how pleased she was to see it used in a more positive way.
Stephanie Weston-Smith, 26, who describes herself as "head spinster" at Spinster's Emporium, a haberdashery shop in Nottingham, is also eager to rebrand the concept with a new "contemporary edge". "I'd like to nudge out that idea of the maiden aunt." She links the rise in the number of young women happy to identify themselves as spinsters to the craft boom and the enthusiasm for knitting, sewing, baking and jam-making; think The Great British Bake Off and Sewing Bee.
But, as Bolick explains in her book, spinsters were once exactly that: spinners. The term originated in 15th-century Europe to describe unmarried girls who spun thread for a living. By the 1600s, the term included any unmarried woman.
It wasn't until the 18th century that "spinster" became synonymous with "old maid". At the time, a woman was a spinster if she was unmarried at 23. Today, the average age a British woman marries is 32.
But the pressure begins much earlier, and is everywhere. From train carriages to television ad breaks, we are bombarded by commercials for online dating sites, happy couples and jolly families. Do you have to succumb, or is it ever acceptable to remain a spinster?
Kirsty Haynes, 27, who works in the London offices of a Swedish broadcaster, says her friends are all at an age when they are getting married. Her Facebook newsfeed is awash with engagement announcements. "They look at me and say: 'Why don't you have someone? You're nice...' Or: 'Coming up to 30... you'd better find someone."'
Kirsty says she tries not to let it trouble her: she has a rewarding job, hobbies and friends. "But if you didn't have those things," she says, "you might dwell and think: 'If I had a boyfriend, I might have more of a life.' But even if I were married, I would still want my own interests."
This goes to the heart of Bolick's argument. A woman must have a purpose and passion beyond simply attaching herself to a man, and must feel happy in her own company.
She quotes the critic Vivian Gornick, who after leaving her husband in the early 1970s, wrote: "The idea of love seemed an invasion. I had thoughts to think, a craft to learn, a self to discover. Solitude was a gift."
Bolick is particularly troubled by how pervasive the myth of Prince Charming and Happily Ever After still is. She tells me she is delighted that children's films such as Frozen and Brave have introduced new sorts of stories to counter The Little Mermaid, Sleeping Beauty and Beauty and Beast, which all end in marriage.
"But it's not nearly enough to erase the staying power of the classic tales still in circulation. My small niece often asks me when I'm going to get married and have babies, just because she doesn't understand yet that there are other ways for adult women to be."
In her closing chapter, Bolick ventures that there is currently a man in her life. "S" is seven years younger and a freelance writer. Talking to him, she writes, is like "wandering through a library of books I've never read... where there's room enough for my own thoughts to roam".
You might say it is a bit of a swizz to discover she is not the classic spinster of her title. But Bolick's point remains: that independence can be preserved, whether in or out of a relationship.
Kate Bolick's 'Spinster: Making a Life of One's Own' (Corsair, pounds 12.99) will be published in the UK in August and is available now as a Kindle download.