Exactly three years ago, a fresh and sparkly Meghan Markle bowled up to meet Kate Middleton at Kensington Palace. It was days after Kate's 35th birthday and the visitor came armed with a gift – a dream diary.

Imagine it. The California actress, dedicated to aligning chakras and posting brunch recipes, handing the future king's wife – a deceptively steely English rose with hockey sticks in her blood – a twee little book in which to jot hopes and thoughts.

It was the first time Meghan didn't read the royal room. And it's a shortcoming that has today made her the divisive woman in the world, less than two years after she married the most eligible man in the world.

In September 2017, two months before the Sussex proposal, I wrote an open letter to the Suits star, telling her not to marry Harry. (While we're reverse crystal ball gazing, there's also the warning to the Brits that they were destroying another golden goose.)

A snippet about the restrictions Meghan would endure forever: "Being a royal wife is much tougher work than it looks. Once the vows are exchanged, newly minted royals become public property and inherit, along with various titles, crushing expectations."

A career woman who loved posting photos of herself lying by Italian pools, she would soon resent the beautiful Windsor prison and its puppet masters, ie Harry's family, who would be impervious to and faintly amused by her 'I Can Change The World' convictions.

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Inset: The gang at Madame Tussauds before Harry and Meghan were removed. Photo: Getty

For the emotionally distant Windsors, being treated like a princess means shutting up, putting up and getting the job done. It doesn't mean being cosseted or having the rellies drop by with casseroles and breastfeeding tips.

Alas. Meghan, as touchy feely as her doomed late mother-in-law, didn't get that. Nobody in the family was interested in the shiny new toy.

Now I'll tell Harry something for free. Don't give up everything you know and love in the name of your marriage and freedom. It's a fool's paradise.

Of course, I support the right of two adults to want a different life in a different place, especially if their perilous mental health is at stake. It's the basis of my original argument against the marriage – it's all about freedom, or the lack of it. So knock yourself out.

But Harry is breezily blowing up relationships which have sustained him his whole life. His decamping leaves the Cambridges knowing their next 60 years are now non-shared, unstinting duty.

Look at the face of Kate, once his best friend, after Harry tossed his grenade into the ranks. She will not forget, probably not forgive.

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Inset: Kate Middleton arrives home after the Sussex bombshell. Photo: Getty

The problem is just as Meghan couldn't hack life in a strange country far from friends and family – no cocktails with Priyanka Chopra, no independence – Harry will eventually find the same situation unbearable.

The decision to abandon ship was reportedly finalised while the Sussexes were on holiday in Canada, where they had privacy and a borrowed waterside mansion and no pesky youth centres to visit.

It's like having your hair beaded in Bali, or thinking you could live in a garret on bread and brie while in Paris. The old holiday syndrome. Everyone's fallen for it.

And now so has Harry. The illusion of a life he could live far from England is a false dream.

More than almost anyone alive, Harry is an Englishman. He was born to the smell of polo ponies, sting of Scottish air, cut glass vowels and doors being opened for sir, literally and figuratively.

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Inset: Princes William and Harry as polo rivals on July 10, 2019 in Wokingham. Photo: Getty

In three years' time, when he's lying on a sofa in North America, listening to a baby monitor and thinking about flogging his business wares while Meghan reads a self-help book and waits for a call from Malala, he'll start wondering.

Her fervent desire to affirm and discuss while creating a social media empire off the back of his family's fame could start to grate.

She in turn might look at him and think, 'Wow, you were hotter when you had power and uniforms and we didn't have to extract money from the Clooneys and Beyonce'.

Harry will miss the family, the rhythm of a life he was unfortunately born to, with its hideous spotlights and expectations, the certainty of history. And he may not be able to get it back.

It doesn't mean he won't still love Meghan. But what he will have given up could crush – not liberate – him.