I am not twenty-five. Astonishingly to me at least, no longer even forty-five. But of course, that doesn’t stop me thinking I am twenty-five, except when I catch sight of myself in the mirror and wonder why my grandmother has stepped in front of me. But there is nothing like being around real twenty-five-year-olds to grasp that strutting about in tartan trousers in middle age is just a practice run for the rug on the knees later on.

Last week I was watching ‘the youth’ on holiday in Greece. Set me thinking about whether I’d really like to be in my twenties again. All that glorious freedom – I was a bit of a late starter on the career front – so I tended to weigh life up in possibilities of travel rather than job satisfaction or progression. So if we take a little snapshot of myself a couple of decades ago – au-pairing in Liguria, teaching English in Spain, grape picking in Tuscany – with now – life seeping away queuing for the car park at Morrisons’ and inspecting the dog’s poo for worms – it’s not looking like a terribly hard contest.

Even worse when you define yourself by the sunny day test. A brilliant summer morning, the type that sends definite shadows across the garden, makes you think ‘ice lolly’ even though you haven’t eaten a Fab since you were ten. Twenty years ago, circa 1990. Bounce out of bed. Oooh goody. Sunshine. Off to the beach in a Ford Fiesta crammed with friends, Silk Cut and the sound of Sinead O’Connor’s Nothing Compares 2 U. Wonder if the boy with the Metallica T-shirt likes you or prefers your best friend. Try to hide fat ankles. Talk twaddle about the importance of ‘principles’ over several bottles of Piat d’Or or Sol beer and loll about leaning on your best friend, wishing you were lolling on the Metallica T-shirt. Marriage, children, pah – just some nebulous threat on a distant horizon. Watch the sun go down, then come up again. Feel carefree, reckless and slightly hungover. Look fresh-faced with bedhead hair.

Fast forward a couple of decades. Sunny Saturday. Oh goody. Let’s get the barbecue cleaned. Must plant that lobelia before it shrivels up in its Homebase pots. Let’s go for a bike ride when you’ve finished cutting the lawn. Oh. Tyres flat. Why doesn’t anyone put anything back when they’ve used it? Well, I definitely didn’t have it last. Now you tell me your homework project on sustainable development is in for Monday. I thought you had six weeks? But this is the last week and you’ve only done the title page? Forget the bike ride. Sit inside on a sunny day. Worry about lack of Vitamin D. Drink moderate amount of wine, careful not to mix red and white, definitely no spirits or beer. Wake up grouchy, early and very hungover. Wrinkles cling around mouth like desperate climbers dangling from a cliff face. Hair looks sparse and stands up in a good imitation of the wild woman from Wookie.

But yet…that freedom. Was it really all it was cracked up to be? I watched those bonafide twenty-five-year-olds. A seething labyrinth of hormones, one-upmanship and strategies to be eye-catching. The fitness instructor with his dreadlocks. The surfer boys with their manes of blonde hair. The nannies with their sing-song voices. That girl, yes, that one, serving in the restaurant, swishing and a-swaying between the tables until everyone has taken notice. All those tiny waists, dark tans, long legs, short shorts. Everyone jostling for position in the gang, staking their claim, their niche in the hierarchy. Made me grateful for fallen arches and chilblains.

Of course, I envied them the traditional gifts of their age. Boobs that sit rather than hang. Youthful skin, which has a stay-put beauty all of its own. Stomachs that don’t waterfall over the bikini bottoms. I wanted to climb up onto the bar and say, ‘Stop worrying about how you look, this is your moment, you’ll never look better than this. The right person doesn’t care that you have cellulite or your front tooth is a bit wonky.’ But clearly, that would just be wild woman from Wookie come alive and my children would cry and hide from me.

I’d love to have the rhythm of youth that makes a Zumba class look cool and Latino rather than a sack of King Edwards on the move. And I fear my moment for mastering the mono-waterski in the teeny-weeny bikini has passed me by. But on the plus side, I’m not battling away trying to find my place in the world. I might not know who I am but I definitely know who I’m not. I don’t choose my friends because they’re ‘in’. I’ve weeded out the mean-spirited and the disloyal. I’ll never have to go to a night club again and pretend to enjoy myself. If I don’t get invited to a party, I no longer see it as social death, the proof that my face doesn’t fit, that my bum really is too big, that everyone was only pretending to like me – I simply assume they were economising on wine. (They really don’t need to do that. I bring my own.) Maybe I’m not free to disappear off for two months at a time – or even a weekend without some careful planning – but at least there’s someone waiting for me when I get home. Even if it’s only to ask me if there is any more porridge/loo paper/Sellotape…