I can't pinpoint exactly when it happened.

Perhaps it was Harry buffooning his way around the Bahamas that sealed the deal, or Kate charming her away around her arts charities.

Perhaps it was during the Royal Wedding last year, when for one day London felt the way people who lived through the 50s say it used to be all the time - with my five-year-old niece padding fearlessly around her neighbour's knees and us adults cheering through a drunken tug-of-war.

But somewhere, somehow, though I can scarcely believe I am saying it, I've become a Royalist.

It wasn't always this way. Like most teenagers riding the giddy donkey of a blossoming social consciousness, I once sought to cast the world in a morality play - whilst 'playing' as immorally as possible, of course.

"Hark at their gratuitous wealth and privilege!" I'd say, "What sort of meritocracy is this when the head of state is nominated by birthright?! They are symbols of centuries of oppression! Haul them out of the palace and turn it into a hospital!" Etc. Etc.

But I've discovered that, as with so many things, morality as you get older is about learning to pick your battles. Though obscene privilege still offends me, it is far more repulsive, for example, to reflect on the fact that the most of the important decisions facing modern, multicultural Britain are being taken by rich, white, privately educated men with enormous personal wealth.

If we were to dismantle the class system brick by brick, the top table of the Royals, even with all their pomp and ceremony, would be the last one I'd touch. Through years of trudging around all the country to sprinkle magic dust on ordinary lives, I'd venture most of them are more in touch with 'real people' than many sat in the Westminster bubble.

But my conversion is about more than just mellowing with age. More and more in modern society, the Royal family are coming to epitomise qualities that, as a nation, we seem in danger of losing altogether.

Where once self-reserve was the highest principle of British social life, the cult of celebrity has lead us to make an astonishing u-turn. Now, self-exposure is king, from teenage girls affecting sexiness on Facebook to middle class intellectuals peppering Twitter with their ennui to TV shows, that now come with an 'open-wound moment' as standard, even if it's something as daft as a cookery competition.

The defining image of Diana's funeral wasn't the thousands of wreaths or the strangers wailing in the crowd but her two brave young sons, somehow managing to keep their head while the country were losing theirs. Despite unrelenting public interest in every facet of their private lives, the royal family, putting aside the odd juvenile or senile gaffe, have managed to uphold that example of decorum, politeness and reserve ever since.

In Kate, we now have an ideal role model for young girls, an anti-Katie Price. Beautiful, yes, but also poised, warm and smart. It is early days, but assuming she decides a life of charity work and public appearances is for her, we can look forward to seeing her set a different example for years. We despair reading that most little girls just want to be 'famous' when they grow up. Thank god we have Kate when they all want - and will always want - to be Princesses, too.

Which brings us next to perhaps the oldest debate surrounding the royal family. Are they value for money? Couldn't the readies be better spent elsewhere?

Well, in the purest sense: yes, of course it could. But then in purest sense, none of the government purse should be spent on encouraging the arts either - because ultimately, the NHS is more important.

But the Royals are Britain's signature around the world. Even if someone did the sum of how much their palaces and servants cost vs the amount they pull in in tourists pounds and found they came up short, I would still see them as value for money.

Travelling in America last year with an English Kate, I know firsthand that even that coincidence was enough to make people squeal with admiration for the Royals. I'd rather the rest of the world think we're all high tea drinking aristocrats with over the top manners than the obnoxious, bleary-eyed reality of the average British high street.

Lastly, I now no longer resent the royals because of their ancestry. Yes, they're great, great, great (etc.) grandparents were a cruel lot, responsible for some extremely bleak periods in British history, but then beyond my grandparents, I have no idea how better my ancestors bear up. For all I know they were religious zealots, mass murderers or the type of people who accept a round when they know they're only staying out for one - but if you tried to judge me on it, I'd feel a little hard done by.

As it is, under the guidance of her Madge - for whom they all express genuine love and respect, another worthwhile example to us all - Will, Harry and Kate are leading the royal family into a new era of public duty that is defined as much by empathy and warmth as it is by the tradition stiff upper lip.

Call it jubilee hysteria, but disliking them has never felt harder.

Follow Sam Parker on Twitter: www.twitter.com/samparkercouk