Last week witnessed the first tranche of 2011 Census results: that choice nugget regarding age, sex and household estimates. The population is – as we realised – getting older. The percentage of the population over 65, at 16.4%, is the highest ever recorded. We have acquired 1 million more people in their 20s over the last decade, many of them migrant workers. Meanwhile, the median population age of England and Wales is 39: 38 for men and 40 for women. Among women, three times more are giving birth over the age 40 than in 1991.

Generation X – those born in the 1960s up to the 1980s – is society's true squeezed middle: evolved from Douglas Coupland's angsty and indolent grunge counterculture to the banal mainstream. Moreover, according to the more excitable elements of the press, it represents a cohort yet to shake off its feckless, irresponsible youth, allowing a rot to set in at society's core. Following a dubious equation between parenthood and its bourgeois trappings (marriage, mortgage) and adulthood, such doom-mongers have taken to shaking a collective choppy finger and bewailing: "Behold, the Peter Pan Generation."

At 41, I am an example of such a phenomenon: single, childfree and mortgage-less. As it happens, I would rather not be dwelling in a mouldering, rented basement, but Tink and I are trotting along just fine. One does, however, become somewhat irked when the denouncers of Generation X issue from Boomer quarters, aka, the most economically cossetted, socially indulged, lotus-eating generation of all time.

The Boomers benefited from the best of Keynesian economics, be it health, housing, education or jobs, many luxuriating in the pension system's last hurrah. Xers, meanwhile, have lived a life pockmarked by recession, were the first generation to pay tuition fees, and left school or university to unemployment and exorbitant property prices. David Willetts's 2010 polemic, The Pinch: How the Baby Boomers Took Their Children's Future – And Why They Should Give it Back, merely confirmed what we already knew: if the Boomers snatched everything – economic and ecological resources, social and sexual rights – then payback was ours.

For the notion that my peer group's reluctance to "commit" is what marks us out as infantilised hedonists is ironic, given that it can also be seen as a reaction to the shoddy parenting of a generation for whom having children was something they did by way of finding themselves, before sloping off to find someone else. Xers are the traumatised products of such misadventures: cautious, wary of commitments that cannot be kept, scrutinising the world sans rose-tinted John Lennon glasses.

To be sure, there is something rather ick about adults in romper-suit leisure wear, LOLing vampires and chillaxin' over Quidditch. However, if there is some sort of meeting-in-the-middle solidarity between Generations X, Y and Z, I, A/O, or what have you, it is because we are the ones left picking up the pieces. As Willetts contends, the pre- and post-Boomer divide is set to be a faultline to rival – and perhaps replace – class antagonism in British politics.

At least we are being honest – embracing responsibility where we can, rejecting it when it is beyond our financial or emotional means. Better a questioning, wrong-righting child than a blue-jeaned, egomaniacal, eternal adolescent. Even our supposed irresponsibility belies a situation in which Xers are working harder with fewer perks, while endeavouring not to over-burden the planet and find new social structures to replace the ones that Boomers have cast aside. The post-war generation talked a good game about changing the world, but it is we who are going out and doing it.

At the same time, the notion of the Peter Pan Generation holds a specific resonance for women of my age. A quarter of us will not breed, the figure rising to half of those with degree-level education. If we are choosing to be Peter Pans, it is because we do not seek to be so many Wendys. I would rather have an "infantilised" life full of narrative, comradeship and adventure than Wendy's plodding existence of mothering, drudgery and domestic confinement. Seen in this context, Neverland provides not a feckless, but a liberational narrative, in which swashbuckling boasts greater appeal than shadow sewing.