Turning 40 was an unexpected misadventure. Unexpected, as I really hadn’t given the event much thought in the run-up to it. I’d never been someone to fret about age – up to that point I’d welcomed each year with excitement and curiosity. Three days after my birthday party, after the presents and the love, I fell off a cliff.

Emotionally speaking, that is. Sudden, mind-bending vertigo overtook me. I looked back at the loss of youth, cool and relevance. And forward at the terrifying prospect of comfy shoes, container planting and Radio 2. Other things were happening at the same time – Brexit, Trump, environmental catastrophe – and the gilded life of a 1990s girl, with all the liberation and hedonism that came with it, suddenly felt so over.

I wrote a book to try and make sense of it all (Now We Are 40, Whatever Happened to Generation X?). I had another baby. I changed jobs. I moved country. I sought out new friends and reconnected with long-lost ones. How dare anyone suggest it was a midlife crisis. Those words couldn’t apply to me, because I was still young. Young, I tell you! Look, I had the midlife ear piercing to prove it.

The piercing was halfway up my right ear cartilage. For two years after having it, I suffered silent agony – a physical reminder of the emotional discomfort I felt about being in my 40s. Finally, one night, feeling a bit stupid, I took the diamond hoop out.

Like many of these crisis moments, peace slowly hoved into view, along with acceptance. I acquiesced to the inevitable passing of time. I was in a different stage of life now, and maybe my 40s had other benefits I could capitalise on: time for my kids to shine, time to enjoy the comforts of being home more, time to go to bed early on a Friday night without feeling like I had weirdly failed. Perhaps, I started thinking, we should move to the country. Still couldn’t accept that lack of edge, though.

Edge was what my generation was brought up with – resistance to the status quo, an unwillingness to follow the rules, a coolness to established tradition and hierarchy and a desire to do things differently. It’s why I wear Margiela, not Toast. Marni, not Armani. And it’s why I had thought that upper ear piercing was a good idea. One day, taking a turn in the Harrods jewellery department (excellent pastime by the way), I came across Shay.

Shay, my hardcore fashion friend told me, was a hot Californian brand all the models loved wearing. The jewellery was truly original yet delicate – not brash and look-at-me, but it certainly had edge, a touch of rock n’ roll. My eyes locked on to a hooped ear cuff set with diamonds and rubies, which I could wear halfway up my ear without making another painful hole in it.

But could Shay make it bespoke? I loved the design but I wanted to make it mine – with emeralds. Emeralds symbolise truth and love, and I’ve always been drawn to them. The ancient Egyptians thought they were a gift from Thoth, God of Wisdom. They also herald intuition, and are associated with sight and the revelation of future events and truths. Emeralds were not just beautiful, they were a powerful sign of the place I had arrived at.

Shay could indeed create a bespoke cuff with emeralds – but I felt guilty about the price. I dropped a few Christmas hints to my family, but it turns out they had other, utterly lovely but, you know, more mumsy ideas for presents. So I put the order in myself. The process felt strangely emotional. Something more than just buying an ear cuff was happening to me. This was about me, the peace I had learned for myself, and the new identity I was forging in this new stage of life.

Six weeks later my ear cuff arrived from California, and was even more perfect than I had imagined. I wore it immediately but not many people noticed. I liked that it was discreet – it was, is, my secret. It means something very personal to me. It is my gift, commissioned, bought and sold to myself. And even if no-one can tell from the outside, on the inside I still feel a little bit edgy. Even when I am accidentally listening to Radio 2.

Now We Are 40, Whatever Happened to Generation X?