The novelist Angela Carter once said to me that one of the hardest parts of her craft was working out what the recent past looked and sounded like. Want to set your novel in the late Victorian period? Easy, you can read books, do research, get the feel of it all, as Carter did so brilliantly for Nights at the Circus. (Sure, it was a work of fabulism, but like all good make-believe it was rooted in the real, then given a sharp and particular skew.)

But try and recreate the look and feel of the recent past - of, say, up to 20 years ago - and it all got much more difficult. When, asked Carter (this was in 1987) did they start pushing refreshment trolleys through trains as opposed to making everyone weave and swerve perilously to the buffet bar? Was it five years previously, or 10? A small point, she conceded, but it shows how the material world changes month by month without us properly noticing, until the moment comes when we want to recreate the physical experience of times that we ourselves have lived through.

I was reminded of the point this week by the news that perms are making a comeback among the young and fashionable. Or, to be more specific, it is the demi-wave that is having its moment in the sun. Salons can't do enough of them, while Superdrug reports that it can barely keep up with the demand for do-it-yourself home kits. While the full-blown perm is always with us - the preserve of an ageing female population that made most of its key sartorial decisions in the 1950s - the demi-wave belongs specifically to the first half of the 80s. Anyone who was young and foolish then will remember it. Instead of looking like your mother or, worse, Brian May, a demi-wave promised to give you "root lift" or "body" or, to be completely honest, a sort of indeterminate kink which was neither one thing or t'other. If you still can't quite picture it, look at Keeley Hawes in Ashes to Ashes, the retro-cop show set in 1981. See that odd mixture of a dead flat parting combined with frizzy ends? That, believe it or not, was the effect that every girl worth her Wham! cassette tape was after.

Seeing that picture of Hawes acted as a kind of Proustian sense-memory for me. Twenty-five years ago women's hair looked and felt different from the ubiquitous poker-straightness of today. Everywhere your gaze fell it beheld an odd combination of flat and frizz fighting for dominance on a single scalp. Everyone you met was either "growing out" a demi-wave or saving up to have one (they were expensive). In short, the nation's hair was in a permanent state of becoming, never settled in a single state. The next time you arranged to meet a friend you never knew whether to look out for someone with a bob of stair-rod straightness, as sported by Pam Ayres, or Kevin Keegan - for all your stylist's promises of a "subtle" look, the demi-wave had an unfortunate knack of mimicking the bubble perm of the late 70s.

So what physical markers characterise our own particular time? It will be impossible to say until 10 or 20 years have elapsed, and all those busy visual details have had a chance to settle into a coherent and enduring picture. I guess it will turn out to be a particular combination of Evian bottles, a certain sort of spectacle shape, and that folded-over way in which everyone ties their scarves these days (as opposed to a Tom Conti-esque Glittering Prizes shoulder-flick). I'll know it when I see it and, just like the demi-wave, it will mark the place where the recent past comes rushing in through a tear in the fabric of the present. More potent than Proust's madeleines, it is the shape of a young girl's fluffy head in profile or the way a hip executive jabs at his iPhone with a too-fat finger that will become the surest way of revisiting the first quarter of 2008.

kathryn.hughes22@googlemail.com