In my head, I’m twenty-nine. The only menopausal twenty nine year old I know, admittedly, but twenty nine anyway. I think it was an age where, despite life being crazy busy working full time with two young children, I was really very happy. So somewhere, on some level, I stopped the clock there. But this piece isn’t about me lying to myself or others about my date of birth – it’s about some real highs and lows of having reached my true age, which, if truth be told, is fifty three. There, I said it out loud. (I now sort of feel obliged to type the words ‘Don’t tell anyone, will you..?’)

On the 'high' side, I’m blessed, extremely so, in fact. I love being a parent to two grown up children, people whom I actually choose to spend time with as adults in their own right. The thought that I've helped form them along the way is a constant source of pride. I love that I still love the same man who fathered them and realise how very lucky that makes me. I am, at last, after my twenties and thirties spent juggling life and my dizzy forties spent meeting myself coming backwards, finally comfortable in my own sagging skin. I have the career I've always dreamed of, having told my boyfriend (latterly my husband) over thirty years ago that someday I would be a writer. And I love being a grandmother! Who knew that would happen?! A few years ago when my eldest daughter, Kate, announced that she was pregnant – at first I was a bit - Oh no, that makes me old. I was so far from ready.

But the day my first grandchild was born, I felt something shift in me. And I'm not talking about an 'Oh, how lovely' moment. I mean something primal, something seismic, like two parts of the San Andreas Fault grinding against each other. My baby has a baby. Nothing will ever be the same for her or me again. I no longer had the same fear of my age or title. Instead I wanted to shout from the rooftops: "HEAR YE! HEAR YE! ESME'S HERE AND SHE'S BEAUTIFUL AND MY DAUGHTER'S AMAZING AND HEY, I'M A GRANDMOTHER!"

This is, though, also an age where I confess I feel exhausted – one of the lows. Tiredness nestles beside the cognitive fog my forgetful brain presents to my 'twenty nine' year old body, plus the unpleasant night sweats and the daytime solar surge moments. And gravity has taken up residence in the fleshier parts of me and my face can almost be heard slurping moisturiser as it passes the jar nowadays. Yep, God, if he’s actually out there, is possibly a man. There are a few design faults with this whole 'retiring-egg-malarkey'…

A friend of mine recently described this time of life as 'the sandwich years' and I remember thinking at the time how perfect a description that was. With my much loved eighty six year old mother at end stage dementia, and living in a nursing-home, I find myself parked right in the middle of her and Esme. It's an emotional time, even without hormonal impacts. On one side I have the exciting flush of new life and the absolute joy and honour of playing a part in another child's life, and the other, I have to watch my mother's sad deterioration and deal with all of the sorrow and guilt that that presents. I am the proverbial filler in the sandwich; feeling love for both, wanting to serve both relationships as best I can and yet…they are so very different.

Each age, twenties, thirties, forties, fifties and any subsequent decade we’re lucky enough to live presents different challenges. Personally, my forties, though busy, were my favourite decade with my fifties, complete with all above mentioned highs and lows, looking like it will assume that role. I'm sort of hoping that the trend will continue – every decade being the best yet. So what if the body overheats and is permanently pointing south? It matters little when a small child whispers in your ear, 'Nanu,' (Yes, that’s what she calls me and I melt every time) 'Why are you …squishy?' and my response while laughing is 'All the better to cuddle you with, my dear.'

Fionnuala's book The Day I Lost You is published by Harper Collins and is available from Amazon now.