There’s no doubt for women of the noughties that Sex and the City is instructive stuff. “Let me tell you something about married sex,” said Becca. Becca is one of those cool, glamorous young things, who features in the novel. (Yes, in between reruns of the TV series, there’s always Sex and the City the book.) “What’s the point?”

“What’s the point of a husband?” said Julie (another groovy glam-pot). “I mean, who needs two babies?”

“I totally agree,” chimes in Janice. “Except that now I want to have another baby. I was thinking of getting rid of my husband.”

It’s sharp stuff. The truisms have a kind of “in-your-face” reverberation.

Even blokes secretly terrified of the neurotic narrator Carrie love to loathe her as she shifts from man-lover to man-hater within a sentence. No doubt when Carrie declared she was missing the “bride gene” – as Julia Baird reminded us in “No rash decision to stare down the barrel of marriage” (Herald, March 10) – most Australian men cheered. Oh joy. This fantasy gets even better. A chick who’s hot for it, but would run a mile at the thought of white tulle and wedding bells.

Baird is right when she says that for women “love and commitment are our battleground now, the place where the struggle for female identity is going on”. Despite the hard-fought battles for liberation, never before in Australia’s history has the place of women in our society been so confused, and the expectations so crippling.

And now we wonder why women of marriageable age hesitate; women of child-bearing age postpone; and successful single women stay just that – successful and single.

The sad truth is Australian women in their 30s and early 40s are a displaced generation. While our feminist foremothers blazed a trail and broke through numerous barriers in the workforce, in politics, in health care, in reproduction and contraception, child care, family support and even in personal finance and economic independence, we nevertheless find ourselves desperately grappling to make it all work. And mostly it doesn’t.

Women’s and men’s lives have changed. But in forcing the change we have broken down some of the fundamental structures needed to keep us all afloat. We all know marriage doesn’t always work. If yours has lasted more than 8.3 years, you’re doing well – you’ve beaten the median. But then a lot of things don’t always work. Pregnancies don’t always work. Families don’t always work. And sometimes trying just doesn’t work either.

But somehow, along the way, even “trying” has become a little passe, and perhaps just a little too risky.

Consider a few sobering facts: almost one in two marriages ends in divorce, and four out of every five women separated from the fathers of their children become the lone prime carer. Top that with the knowledge – to which everyone in a competitive work environment will attest – most women who take time out from a good job to raise children will be penalised by the workforce. Given the blatant realities, is it any wonder women are holding off marriage, or simply staying solo?

But there is also another much darker reason women in their 30s and early 40s are alone. And perhaps this is of our own making. The mating rules have collapsed. And we, women and men, have allowed it to happen.

Those unwritten rules that drive romance, courting, love and an oath to commitment have disintegrated. And we’ve largely given up on the structures that once supported these rituals, such as engagements, marriages, vows “for better or worse, till death do us part”, and so on.

The problem is we haven’t really replaced the old-fashioned stuff with anything better. Living with a lover is as simple as shifting a bit of furniture. Leaving can be just a matter of handing your keys back. We’ve made it easy to walk out, walk away and move on: each time steeling ourselves against further disappointment. In the end, the lesson is a selfish one about individual preservation and the protection of “me”.

All of which is fine, if we want to remain alone, or in the transit lounge of commitment.

Zygmunt Bauman, the British sociologist, laments that modern-day relationships are increasingly characterised by a “permanent temporariness”, a state of living where the partnership has no real structure to ground it. And, of course, the deal is easily cancelled if one party wants out.

For men in particular, such “permanent temporariness” might seem a pretty good place to be, while they drag their adolescence well into their 30s and even their early 40s. With plenty of guilt-free sex readily available, and the ties of commitment and responsibility pretty thin on the ground, men really are “having it all”.

It may not be a lack of desire to settle, commit or marry that distinguishes a growing generation of Australian men, but rather it is a lack of need.

And perhaps women like Carrie who declare an allergy to weddings and a lack of “the bride gene” should also dig a bit deeper and ask why? And what am I going to do about it?