Turning 38 is tough. Awkwardly wedged between blithe youth and the inexorable pull of middle age, it can be something of a no man's land.
Pity Kate, Duchess of Cambridge who had an even tougher time hitting this particular milestone this week after her big day was spectacularly overshadowed by the news that Harry and Meghan, the Duke and Duchess of Sussex had decided to effectively quit royal life.
On her birthday, Kate was photographed driving into Kensington Palace wearing a decidedly un-regal olive green puffer jacket and looking strained, all in stark contrast to the official shot that went out on Instagram of her looking impossibly glamorous perched on a fence.
And, who can blame her for looking a tad miserable? Currently, the Queen, Prince Charles, Prince William and Prince Harry are working to hash out the details of quite what the couple's exit will look like, including what royal work they will undertake, where they will live and how they will fund their new life.
However, the question of what life for the remaining working members of the royal family will look like looms large and for Kate, the picture is far from pretty.
While Harry and Meghan have indicated they will continue "to honour our duty to The Queen, the Commonwealth, and our patronages" however there is no indication what that means in real terms.
In 2019 they undertook a combined 284 official engagements but if they are also living in North America, just how many will they realistically be able to clock up? Therefore, on a rudely practical level, someone is going to have to pick up the slack.
However, the ramifications for Kate go far beyond simply having to do the job of smiling and waving for two (or three) people.
In 1936, when King Edward VIII abdicated to marry Wallis Simpson, the new King George VI (the Queen's father) essentially exiled him to live in France. By all accounts, Edward believed that after his marriage to the American divorce and a suitable period of Gallic contrition his brother would let him return to the UK.
He was cruelly mistaken. George VI knew that having two Kings, albeit even a former one, on British soil would detract from the remaining monarchy. Thus, Edward and Wallis were forced, save for a brief stint in the Bahamas during World War II, to live out their days aimlessly hobnobbing with the beau monde in Paris and trying to find a way to fill the endless days.
With Harry and Meghan breaking free from the Queen and Co. a similar prospect now clouds the royal family's future, but this time simply shunting the recalcitrant members off the Continent isn't going to sort things out.
No matter where the Sussexes go, they will be the object of obsessive, frenzied global attention and their new lives, and by extension their unofficial court, will cast a very long shadow over the Cambridges.
Unfortunately for Kate, she faces having to bear the brunt of this royal world order. There is no getting away from the uncomfortable fact that no matter how unfair (or un-feminist) it is for Kate to be constantly pitched against Meghan, this situation is only going to be thrown into overdrive in the coming months and years.
Consider this. Until now, the two women were on roughly equal footing. Both are in their 30s. Both are mums. Both are stunning. They have the same title and the same incomes - but all that is about to extraordinarily change.
To start with, the Duchess of Sussex is likely to end up with a far bigger fortune thanks to the couple's plans to pursue financial independence. Six, seven or even eight-figure deals are all very, very likely, leaving Meghan with a truly impressive personal war chest.
Given she will no longer have to justify her spending, there is every chance we are going to see her fully realise her sartorial ambition and become a truly iconic fashion figure. Hello Paris couture week. Adios Zara tops and thrifty recycling.
This situation goes far beyond the simply superficial.
With Meghan freed from the shackles of royal tradition and protocol, we are likely about to witness the nascence of a global phenomenon – and brand – the likes of which the world has not known before. Think Diana. On steroids. With a private jet. And an Instagram account.
Unfettered by tradition, Meghan and Harry are now free to become the true international power players they have long sought to be, dynamic and unstoppable. It's a heady thought no?
And if and when this comes to pass, Meghan would eclipse Kate in every significant respect.
While Kate is at home in Britain dutifully opening gardens, talking about early childhood development and stocking up on knee-length tea dresses, I think we can expect to see Meghan prosecuting a sweeping agenda with a global reach. Think, quick dashes to Africa to promote female education. A side trip to New York to address the UN. Speaking engagements at the World Economic Forum. And, all the while, she will most likely be enjoying an unsurpassable Instagram reign. This is Meghan unleashed and it is going to be thrilling to watch it unfold.
• Harry and Meghan's resignation from the royals comes with a hefty bill
• Prince William's last-ditch attempt to end Harry rift before bombshell
• Kiwi who broke Harry and Meghan story reveals what's next for royal couple
• The photo that revealed early troubles for Harry and Meghan
That is, if you are not Kate.
Since joining the royal family in 2011 she has acquitted herself superbly, duly producing three photogenic children, toiling away at her chosen charitable causes and impressing the Queen with her redoubtable work ethic. Essentially, she has done everything right and has a blemish-free royal report card and yet she faces having her achievements pale in comparison to Meghan's.
No matter the inequity of it, the Duchess of Cambridge is never really going to be able to escape the global shadow of her high-reaching, high-achieving sister-in-law. With an exploding international fanbase, a growing fortune and the (let's face it) better looking Wales brother by her side, Meghan looks set to come out on top.
So, happy birthday Kate. Let's at least hope your cake tasted good.