The other day as I sat on my sofa in front of a log fire watching Friends on Netflix with my younger son, I had a small epiphany. I felt completely contented.

It wasn’t the fierce, knife-edge bliss of youth, which draws intensity from proximity to the precipice — that was a time when I said yes to reckless love affairs and went to Croatia during the Balkan wars. Nor was it the self-bolstering glow of middle-youth (30s and 40s), when every personal or career triumph adds points to a futile tally maintained only by you. It was just this quiet sense I could look around me and feel what I had was enough.

On the other side of the wall, my husband was listening to Radio 4 and my teenage son was talking to the Maine Coon kitten. I was in the house my spouse and I bought together with a mortgage we repaid two years ago. I could account for everyone I love most, they were healthy and I wasn’t sobbing from financial anxiety. Aged 51, I realise these are the true, most important requirements of happiness. I didn’t know until now, however, that I am a living cliché.

The Resolution Foundation has sifted through seven years of data collected by the Office for National Statistics and announced recently that 51 years of age is the turning point: the moment when you’re over the miserable hump of turning 50 and due to experience feelings of higher self-worth and lowered anxiety. The findings tally with Jonathan Rauch’s research for his recent book, The Happiness Curve, which also concluded happiness slowly decreased in your 20s and 30s, before nosediving in your late 40s and then — thank goodness — recovering once you’re past 50, edging upwards until you hit 80.

This all feels so true it spooks me. A year ago, as I turned 50, I felt so glum I couldn’t bring myself to have a party. There’s something about arriving at your half-century that feels like a reckoning in a movie. You realise with a shock it’s more than 30 years since you left school and you’ve not written a great novel, made a scientific breakthrough on the scale of penicillin, or changed the fortunes of thousands through philanthropy.

I did not grow up to marry David Bowie, as I once imagined. As I moved through my 40s, I increasingly felt I had a date with the menopause. It seemed like everywhere I turned, an older woman was saying doomfully: “You become invisible when you turn 50.”

However, a year on from my Mariana Trench of gloom, life seems very different. After my first full year in my 50s, I can honestly report that I’ve finally got over myself. As the clock turned five-zero I neither shrivelled to a toothless hag, nor did people look through me like I no longer existed. But by far the best part of turning 51 for me is the sensation I’m finally on my way to being a wise, witty, doughty older British woman of the type I’ve always admired. I’m thinking of the late Diana Athill and Baroness Trumpington, both of whom made grown men quail (and blush) and talked piercing good sense until the end.

I now understand why my mother said so often in her 50s, “I’m so glad I never have to be your age again.” Quite right. Most people’s teens and 20s are an exhausting time, full of insecurities and vain quests after false grails. My own youth was dogged by twin desires to be thin and in love, meaning I wasted years being bulimic and meeting all the wrong men.

Aged 51, my goals are so much saner. I want to learn some simple dance steps, to speak French fluently and immerse myself in the history of art. I want both my sons to be happy and my husband to stop saying he could drop dead tomorrow. But I won’t weep if some, or none, of this happens. I’ve made my peace with disappointment. And if you’re not easily crushed by life’s failings, the only way forward is up. No doubt about it, the water’s balmy at 51.

— The Telegraph Group Limited, London, 2019

Rowan Dorothy Pelling is a British journalist, broadcaster, writer and stand-up comedian.