So the final spell has been cast on the world of a certain Mr Potter (yes, when you read that, the voice in your head will always be Alan Rickmans). And as countless fans will doubtless be seeking a helpline to cope with their Wizard Withdrawal, there are also many who may question the success of the boy who lived, and thrived.

For no spell, from the most whimsical Wingardium Leviosa to the deadliest Avada Kedavra will come close to matching the spell that J.K. Rowling has cast on the globe since the first book was published in 1997. She has enchanted, bewitched and enthralled children and adults alike. There aren’t many children’s books printed with alternative covers so that grown-ups don’t get embarrassed on the tube on the way to the office. Neither do many children’s movies shatter box office consistently records from the first second of release. No. The eponymous Harry is a phenomenon. No doubt about that. Just about everyone loves him, well apart from two blokes and a girl in their early 20’s who came second to Radcliffe, Watson and Grint in the audition process and must want to vomit every time they see a Potter poster. Which at the moment would be every 20 seconds! So the question is, where did she go right?

The story itself is not a new one. In fact, its origins go back for millennia. Good versus evil, good faces a challenge, evil gets to the brink of success, good ultimately triumphs, but always with some sacrifices and lessons learned along the way. As those bloody meerkats would say, simples.

Well I have a theory. And it’s only my theory, and maybe, like the stories themselves, not even an original one, but it’s mine for the moment so bear with me.

First, in a stunning prediction of what was to happen in the years since 1997, she started off by making Harry Potter famous for not having done anything. She made him a 21^stcentury celebrity. How did J.K know that not only was celebrity, but this particular kind of celebrity, going to be one of the defining factors of the young century? For in the “Philosopher’s Stone”, that’s what Harry is. He’s famous. He didn’t actually do anything apart from be in a room, at a certain time when something happened, and TA-DAH! He’s a wizarding Peter Andre! This is very smart, because it sets Harry a whole set of challenges along the way, and of course he doesn’t stay as useless as Peter Andre for long. He immediately sets about working to justify his newly found status. But Rowling was smart enough to recognise that, celebrity in a school is a very tough challenge. A lot of kids want to be the Head Boy, or captain of the hockey team. But when you get there, a whole new set of challenges can befall you, much more hideous than the One Who Shall Not Be Named. Jealousy. Bitching. Back-stabbing. Treachoury. A school is a tough place for any kid at one time or another, but for the talented and the successful, it can be a forbidden forest. Frightening, dark and forboding. Harry faces this challenge at Hogwarts from day one. And these flaws are brilliantly exposed throughout all the books. He falls out with just about everyone. Faces derision, exposure and malice, not from Voldemort, but from his classmates, even at one point, the ever-faithful Ron. (see, I don’t even have to say Weasley, he’s even above Barker and Corbett as the most famous Ron ever now)

This smart move made Harry both legendary and vulnerable at the same time. He has to earn his celebrity. He has to graft to be a hero. He has to prove the legend right. Lesser boys would have run away and cowered, but J.K made him a battler, but a likeable and believable one. So we can all connect with Harry. Some because they were that school hero and had to cope with the traumas, others because we wanted to be them, and carried all the jealousies and bitterness that is a natural part of the passage through school life. Because of this, Hogwarts for all its moving staircases and hidden rooms would always be grounded in reality. We all felt connected to it, because it wasn’t a haven of safety or comfort zone. It was a bloody school.

A second part of the genius is quite simple. It’s all terribly British. But more than just that, she immersed Potterland in everything that the world, and particularly the USA sees in us as the three most important aspects of British-ness. John Cleese put two into the brilliant “A Fish Called Wanda” and American audiences loved it, namely, eccentric and quaint. Rowling added a third, gothic. In fact, three things that America loves but can’t recognise in themselves. It’s why they can’t get enough of the Royal family and Simon Cowell – the extreme is intentional – these qualities make us something that our American cousins can never be.

Put it this way, if Earth had the structure of a typical school, the United States would have to be the sport lovin, big jawed, jock. They are the hero of the day who always gets the girl. The Brits represent all the things that America can’t be. But they love these qualities in us.

Another point of genius on the part of Ms Rowling was the language. She gave a generation of Potterites – is that right? Is there a Potter equivalent of Trekkie? Anyway, she gave them a language they could use and play with. And one that was much more effective than “bang bang, you’re dead”. For kids playing at Hogwarts, the language of the spells makes play so much more enjoyable. By saying the magic words, your play-mate knows exactly how to react. “Acchio” and you appear, “lumos” and you can see in the dark, “Evanesco” and you disappear, “Wingardium Leviosa” and you pretend to levitate, “Avada Kedarva”, your dead mate! It was fun when I made the lightsabre noises in pretend Jedi battles as a kid, but my play mates just never knew when to bloody die. With the killing curse, there is no doubt. What fun that must be for children. I’m jealous.

Not one child under 14 in western society has ever not known what the word Muggle means. Or Half-blood. And all these terms leave children in no doubt that prejudice exists everywhere. You can see the origins of words that we now dare not use in relation to black people or Asians in those words. How innocently the word Muggle is used by the inhabitants of Harry’s wonderous world. Until someone is called a Muggle Bastard, then everything changes. Then it becomes the “M” word. Now that never happened, but Rowling certainly went down that route with Mudblood. A serious lesson for kids growing up in a world that faces prejudice all the time. Whether implied or otherwise, she insisted that all worlds have bigots. But Harry and his supporters were tolerant, open minded and caring. Harry faced prejudice full on for the first 11 years of his life. He was a magical Mandela, trapped in hell under a staircase, until the day where he could freely be who he was, without judgement. And we can leave our children no better lesson than that.

One can only wonder if J.K. Rowling had this planned all along. Was her insight into Harry’s celebrity and fully formed world of Muggles and magic so skewed to a global franchise all just a coincidence? I’d be even more impressed if it was, but either way I really don’t care.

I will miss Harry, Hermione and Ron. The journey has been fun. I’ve laughed, cried and screamed. I can’t begin to imagine how much more fun it would have been if I were 14. Thanks J.K. Now, EXPELLIARMUS!