Opinion: The generation gap is vanishing, says Rachel Moore, 53 going on 21...

At the weekend, my younger son turned 18. The next day was my 53rd birthday.

To celebrate his milestone, we went to eat in Norwich, driven by his 20-year-old brother.

The music he chose for the trip spanned the last 25 years, favourites of us all. Three decades separate us in age, but we share musical tastes.

At the restaurant, a twentysomething waitress asked where I had bought my dress because her young colleague loved it (Asos, if you're interested, where the 16-60-year-olds buy the same dresses, shoes and jeans).

Later, at a bar, my older son educated me in the finer nuances of Love Island, a TV series watched by twentysomethings to 50-plus.

I thought back to my own 18th birthday, and how different our relationships were with our parents and the yawning chasm in what we did and what we liked.

Being 53 sounds old in the context of then, but feels anything but.

'No way are we 53. I feel no different to 21,' I told classmates from the 1970s, who wished me Happy Birthday on my Facebook timeline.

At 18, 20 or 25, I wouldn't have been seen dead in a bar with my mother, or her with me. No twentysomething would have ever asked her where she bought her clothes because they were mum clothes.

Mums were mums, however stylish, and felt at least a century older. They yelled at us to turn down Top of the Pops on Thursdays. That music was our music. 'Is that a boy or a girl?', they asked in horror when Boy George and Culture Club were on? Radio Luxembourg was subversive to them, driving us to our bedrooms to listen 'to that rubbish'.

Today, we enjoy the same music as our young adult children. They listen to our Joy Division and Oasis. We wear the same jeans and Converse as them, we shop in the same places.

Mutton dressed as lamb is no more. Clothes and style are ageless.

Parents and children go to UEA Nick Rayns LCR gigs together, enjoy the same TV and films, and have more in common than parents do with people a decade or so older.

This all means we spend more time with our older children, have greater understand of who they are and have better relationships.

When I was 20, being 53 meant dotage almost, winding down in conservative mum clothes, comfy shoes and elasticated waists.

Instead, I'm growing my dyed blonde hair (to cover the grey) longer, going to a gigs and planning new active hobbies when my 18-year-old leaves the nest for university in September and it's my time.

It's not Peter Pan syndrome. Forty-plus women look, feel and live differently than the generation before, believing the best is yet to come.

In fact, middle-aged is obsolete. 96% of 40-plus women don't feel it. Nine out of ten believe they have a far younger attitude than their own mother's generation at the same age

Marketing agency Super Human found four-fifths of women felt society's assumptions about middle-aged women did not represent how they live their lives.

More than two thirds considered themselves in the prime of life.

Women's confidence and ambition is behind much of the change. Neither stops at 40, both keep on growing.

Divorce and singledom – no longer a stigma – are producing warrior-like over-50s women, driven and optimistic about the future, excited to explore and experience what comes next.

The thought of retiring is as appealing as the thought of dying.

They don't define themselves by age.

While marketers are obsessed with the young millennial, it's 'perennial' women – the no age mindset women – they should be targeting.

Brands have yet to catch up and see how much midlife women have changed.

By 2020 up to a third of the UK workforce will be 50-plus and control four-fifths of the wealth.

The beauty in this seismic change for women in their fifth and sixth decades isn't purely selfish; the shared interests and cultural references bring greater understanding between the generations and closer, healthier relationships between parents and children.

What's not to like? Bring it on.