It’s just past midnight when we step out of King’s Cross. Shaftsbury’s Eros is directly in front of us; next door is the entrance to the Leicester Square tube. It’s got to be 30 degrees out, the air thick and soupy with humidity. Everything’s wrong, but then, everything feels incredibly right: into the tube entrance and around a corner, Diagon Alley blossoms before us. When we first crossed that threshold, at dusk, the street had been teeming with Muggles; in the time it took us to journey up to Hogwarts and back again, the street has been cleared. We’re sharing it – the wizarding shops, the cobbled streets, the perfectly rendered tucked-away corners – with a few hundred people in house robes, hopped up on Butterbeer. Basically: it’s a scene of total magic.

The wacky geographical mash-up is a segment of Universal Studios in Orlando, Florida, known as the “London Waterfront”; it sits beside San Francisco, which sits beside New York, naturally. The late-night frolic in the theme park’s most magical bit, the Wizarding World of Harry Potter, was an event called “Open at the Close”, a reference any Potter fan will catch as well as a literal description: the park, with its pitch-perfect replicas of Diagon Alley and the streets below the Hogwarts Castle, were kept open until two in the morning for ticket-holders from GeekyCon, a four-day fan convention that would begin the next day.

GeekyCon began in 2009 as LeakyCon, taking its name from the massive Harry Potter fan site “The Leaky Cauldron” (which took its name, in turn, from the pub on Charing Cross Road that serves as the gateway to wizarding London). LeakyCon began as a space to get together and celebrate the Harry Potter universe, but within a few years the scope had broadened so far beyond its origins that a rebranding was in order. This year, my first time attending the convention, was the first under this new name – I was curious about what that would mean in practice. But it felt fitting that the con still began, as many of us began, with Harry Potter.

***

For an entire generation, Harry Potter is a core text; for many, it’s the core text, formative not only because of its content, but because of the collective experience of reading it. The long waits between books, the midnight release parties, the broad cross-cultural anticipation that was near-unprecedented in the book world at the time: for the massive number of people who read them as they were first published, these things are tied up in our memories of reading the books, and our lasting interpretations of their words.

There’s been a lot of press in recent years about how Harry Potter left its readers better people than when they started – last year’s much-publicised study in which a researcher concluded that the Potter books worked to increase feelings of tolerance is a prime example. But Harry Potter also left its fans better readers than when they started: they are gateway books, to new genres or to reading more or to simply reading at all. And for many, it was the act of reading together, in a fandom, that stuck: sharing ideas, influencing fellow readers, taking part in a million small conversations that amount to one enormous collective conversation, from one book to the next.

I was there for all for all of that – until I wasn’t. Harry Potter and the Deathly Hallows was published in 2007, and my deep investment in the Harry Potter fandom fizzled soon after. For the better part of a decade, I’d been in love with simply thinking about the universe, mired in what-ifs and curiosities and endless speculation; my fanfic addiction, writing a few dozen stories and reading, oh, maybe a few billion more, partly stemmed from those spinning possibilities. There were a lot of theoretical doors, hints from J K Rowling and ideas from people like me, those who read passages over and over again, looking for new insights between the lines.

Inside Diagon Alley at the Wizarding World of Harry Potter, Florida. Photo: Getty

Many doors had been nudged open over the years; the final book slammed most of them shut (allow me to whisper the word “epilogue” here). For me, it wasn’t a “hurl the physical text across the room” sort of ending, but more of an anticlimactic emptiness. My favorite fan fiction writers were decamping to new fandoms at a frightening speed; I wearily packed up and followed them. And because online Harry Potter fandom had grown on-pace with the way the web expanded and changed over those years, I had a template for my online enthusiasms now.

But while I was out chasing the Doctor across time and space, while other Potter fans were getting lost in an infinite number of fictional universes, the Harry Potter fandom lived on, and it morphed into something new. The wizard rock community blossomed; fan tribute and parody shows grew so popular that their creators and performers developed massive fandoms in their own right. And even after the final book and the final movie, brand-new readers were coming onboard. They came at the stories in new ways – with different collective experiences, a full set of films to compliment the books, and a creator who always has more to say about her world. The conversation around the series has shifted, but if anything, it’s simply grown more massive, a snowball picking up enthusiastic readers as it barrels down the hill. And for those readers who got picked up long ago, the lasting effects of Harry Potter fandom are making themselves known.

***

The woman behind GeekyCon is Melissa Anelli, and Harry Potter is at the heart of her origin story: she spent much of the 2000s at “The Leaky Cauldron” and wrote a book called Harry, A History. (I’ll never forget her interview with J K Rowling around the release of Book 6, the first time I heard someone asking the right questions rather than journalists squandering opportunities asking silly ones.) We talked about new Harry Potter readers, and old Harry Potter readers who have migrated to new fandoms. “Because the Harry Potter canon is whole, and people can just read it, they’ll feel all the same passion that we’re feeling, that the old-school fans felt for so many years when they were waiting for the new chapter,” she told me. “But then that kind of passion naturally lends itself to stories that kind of naturally branch off from it, like The Hunger Games, or Marvel: regular people rising to superhuman heights, or superheroes being very human. All of those stories seem to come of a piece and inspire the same kind of passion and excitement – they very naturally lead into each other.”

Part of that networked passion comes from the way we communicate online today: we share bits of ourselves on social networks – and sometimes, if we’re amongst the right crowd, we share whole pieces. It’s different to the early days of the web, when we burrowed into niche corners. There are big entryways into the spaces on the web where people get excited about things, and one of them is still Harry Potter. “I think a lot of people feel like, “Oh, I love Harry Potter,” Anelli said. “And they go online and they find friends who love Harry Potter, they start following them on Tumblr, and they see them post about some TV show they like, Supernatural or The Vampire Diaries or a book they’re reading...I think that we’re all leading each other to the things that we love, because we’re all connected now.”

That passion is hard to miss online, but sometimes you need to gather it all up in the analog world. Enter GeekyCon: four days in Orlando, Florida this year (it’s been held all over the country), an event with all the hallmarks of a fan convention – special guests, panels, autograph signings, more awesome things to buy than a person should be exposed to at one time – but without other fan convention hallmarks like endless lines or paying extra money to meet someone famous. Autographs are done by lottery; programming is so plentiful you find yourself rushing from panel to panel rather than waiting in a day-long queue for an hour at the main stage.

Butterbeer! Photo: Getty

I travelled down to Florida with only a vague sense of what to expect. The crowd, by rough visual estimate, resembled the online fandoms I encounter daily: majority female, visibly queer-friendly, with most attendees in their twenties but a sizable number of teens – even pre-teens – with very patient-looking parents in tow. There was a ton of cosplay, some of it staggeringly elaborate – on average a much better selection than from the hubbub of San Diego Comic-Con, where I’d been a few weeks prior. But more striking was the incredible number of attendees casually donning Hogwarts robes or house ties. I didn’t go to a single Potter-focused panel over the four days and yet black robes with house crests filled up every audience; I watched Slytherins and Hufflepuffs (and Syltherpuffs!) pose for pictures with YouTube stars and YA authors. On Harry Potter’s birthday, which fell in the middle of the convention, party hats were everywhere.

There’s something in the air at GeekyCon – a collective pent-up exuberance, bubbling to the surface all at once. You get the sense that this is one of the few times of year that a lot of people have to let out all their uncool enthusiasms to an equally receptive audience – in person, anyway. (I’d say it was for me, too, but now I get to do that year-round, professionally!) At an introductory panel on the first day of the convention, Leaky/GeekyCon veteran Dani Palmer told a crowd of first-timers, “We’re all weird here. That’s the point.” Permission granted to lower the barriers we erect around the things we love – thousands of people, united by enthusiasm.

Anelli makes it clear that newcomers are welcomed – even encouraged. “Passion isn’t defined by how much you know about a specific fandom, it’s just how you feel,” she told me. “And how you feel isn’t quantifiable by how much trivia you can spout. Being less than receptive for people who want to know more, people who are just getting into fandom – it harms fandom. The only way to make it better, the only way to make it bigger, is to say, ‘Come in, come in, let’s share. I’ll tell you what I know: let’s talk about everything.’”

***

Harry Potter isn’t over: a trilogy of new films begin next year. Fantastic Beasts and Where to Find Them, based on a Hogwarts textbook, will be set in New York City, approximately seventy years prior to Philosopher’s Stone. And J K Rowling releases a new fact or in-universe short story approximately every twenty minutes these days, so who knows what the future has in store. But c’mon, Harry Potter’s never over – many of its fans grew up with it, and now, they’re bringing it into the professional world. Scores of professional novelists put down their textual roots writing Harry Potter fanfic a decade ago. Online parodies and tributes are leading to professional acting careers. And for some, it’s the books’ messages, the ethos of it, that’s internalised and spread. The Harry Potter Alliance, who have a huge presence at GeekyCon, are a prime example: the non-profit’s broad range of progressive campaigns are informed by the lessons of Harry Potter, and spurred by the communal power of fandom to do good.

At GeekyCon, there was a whole programming track dedicated to becoming a “full-time geek”, and these ideas seemed to be at the heart of it: some of the guests were so obsessed with something, Harry Potter or otherwise, that they made it a career; others used their experience obsessing over something to parlay the skills they developed in fandom into a career. At these panels, I watched eager parents take notes and ask questions; these were people who supported their young teens’ passions so much that they accompanied them to a fan convention (and sat as patient chaperones at the Yule Ball), but they wanted to know if that passion would be marketable someday – if their children could keep on loving things deeply into adulthood.

The Hogwarts Great Hall. Photo: Getty

This is the fundamental shift in the time since Harry Potter: these days, the answer to that question is yes. Whole industries have grown up around collective enthusiasms online; the entertainment industries have finally caught on that they should go after the audiences that are inclined to really love stuff – and you need experts to do that. The guests at Geeky were well-chosen to show the fannish paths to success: many of their enthusiasms matched the enthusiasms of their audience, and rather than distancing themselves, they totally embraced it – and let the crowd know what an asset it could be. On one panel, young adult author Marie Lu talked about how she drew Harry Potter fan art as a young teen, and how she feels connected to her readers’ passions. “That was who I was, too.”

It’s easy to feel disconnected from a thing we once loved: we cast off earlier passions as childish, disown them as a different time in our life. It takes a great deal of bravery to celebrate them, and to continue to celebrate them, without shame. GeekyCon is a long weekend where everyone is free to be themselves, even if that means they talk a little too much about their favourite fictional character. But it also teaches people not to hide that self when they return home. And the lesson for me? Just because it’s been a while, just because my theoretical doors slammed shut, just because people kept on loving the series in different ways after I’d left – all that doesn’t mean I have to stop loving Harry Potter. At a Harry Potter and the Potters concert in the convention centre, dressed in a Hogwarts track jacket I bought in 2002, I sang along at the top of my lungs with the rest of the crowd. I remembered what it was to love this thing – together.