The cast and crew of Harry Potter reunited to celebrate the 20th anniversary of the first film’s premiere, tickling the nostalgia cogs of muggles and magical folk around the world.

For just over an hour and a half, the films’ stars including Daniel Radcliffe (Harry Potter), Rupert Grint (Ronald Weasley) and Emma Watson (Hermione Granger) reminisced about their lives on and off set.

Some of these tales were simply delightful, while others gave us a greater insight into life behind the scenes.

Here are seven things we learned from the magical Harry Potter reunion.

1. Emma Watson considered leaving the franchise

Watson remembers feeling lonely and how fame “hit home in a big way”. Photo: HBO Max

It’s impossible to imagine anyone but Watson as Hermione Granger, but the actor considered leaving the franchise before the fifth film.

“When I started, one thing that [the producer] and the studio spoke to me about was Emma is not sure she wants to come back and do another Potter,” said David Yates, director of the fifth movie.

Although Watson had opened up about this previously, the reunion allowed fans to hear her speak about the experience with her co-stars.

Tom Felton (Draco Malfoy) said: “People definitely forgot what she took on and how gracefully she did it.”

He explained that while Radcliffe and Grint had each other and Felton had his friends, Watson only had herself.

“I did find a diary entry that was kind of like, hmmm,” Watson said. “I could see that, at times, I was lonely.”

In a conversation with Grint, Watson explained that she feared the fame.

“I don’t know if you ever felt like it got to a tipping point when you were like, ‘This is kind of forever now’,” she told her co-star.

Speaking later, Grint told the camera that he did have similar feelings to Watson.

He did contemplate life and wondered what it would be like if he just called it a day, but they never spoke about it together.

“I guess we were just kind of going through it at our own pace,” Grint said.

“We were kind of in the moment. At the time, it didn’t really occur to us that we were all kind of having similar feelings.”

Radcliffe attributed this to everyone being kids.

“As a 14-year-old boy, I was never going to turn around to another 14-year-old and be like, ‘Hey, how are you doing? Like, is everything OK?'”

Ultimately, Watson said she was grappling with the fame and the idea that there was no turning back. If she was going to step away from this life, it was now or never.

But no one had to convince her to stay.

“The fans genuinely wanted us to succeed, and we all genuinely had each other’s backs. How great is that?” she said.

2. Jason Isaacs originally auditioned for a different role

Jason Isaacs was already slated to play another villain in another movie. Photo: HBO

Jason Isaacs originally auditioned to play Gilderoy Lockhart, the ego-centric (lying) adventurer who stole other people’s adventures and erased their memories, introduced in Harry Potter and the Chamber of Secrets. 

But after he read for the part, director Chris Columbus asked him if he could read for Lucius Malfoy, Draco’s cruel father.

“I’m convinced I ended up playing Lucius because I didn’t want to,” Isaacs shared in the reunion.

“I was about to play Captain Hook in Peter Pan and I thought, ‘I don’t want to play two children’s villains.'”

Reluctantly, Isaacs read Lucius’ lines through gritted teeth … which was exactly what Columbus wanted.

3. JK Rowling was in the reunion, sort of

Before the reunion even premiered, it was revealed Harry Potter author JK Rowling wouldn’t be in it.

Many people chalked this up to her often transphobic views. Stars of the films, including Radcliffe, Watson and Grint, have all spoken out against the author, which may explain her absence.

Still, Rowling appeared in the special through archival footage.

The footage, from 2019, included Rowling speaking about the search for an actor to play Harry Potter. That said, the inclusions were very brief.

4. Daniel Radcliffe had a secret crush

Radcliffe and Carter reunite at Gringotts Bank. Photo: HBO

Before the reunion, Helena Bonham Carter dug out a letter Radcliffe had written her after she asked him for his autograph.

Carter, who starred as Death Eater Bellatrix Lestrange, asked Radcliffe to read it out during the reunion.

“Dear HCB, it was a pleasure being your co-star and coaster, in the sense that I always ended up holding your coffee,” he read.

“I do love you and I just wish I’d been born 10 years earlier. I might’ve been in with a chance. Lots of love and thanks for being cool.”

Naturally, Radcliffe felt embarrassed reading that last part, but Carter said she will always treasure it.

5. One of the Weasley twins broke a director’s ribs

James Phelps (left) recalls the time he broke his director’s ribs. Photo: HBO

In Harry Potter and the Goblet of Fire, the Weasley twins (James and Oliver Phelps) attempt to illegally enter the Triwizard tournament. But their plan goes very wrong and the twins end up wrestling on the ground.

As they filmed the scene, director Mike Newell noticed the twins weren’t putting their hearts into it. So Newell decided to set an example by asking one of the twins to wrestle him.

“I was a tubby 60-year-old gent at that stage and, uh, I really shouldn’t have done it,” Newell said.

But he did, and James Phelps accidentally broke his ribs as a result.

“I was in absolute agony from then on, but of course, the wonderful thing was that I had made a complete twit of myself and everybody felt much better for that,” Newell shared.

6. Richard Harris though Fawkes was real

Original Dumbledore actor Richard Harris made a (robotic) friend on set. Photo: HBO

Richard Harris played Professor Albus Dumbledore in the first two Harry Potter films before his death in 2002.

At one point in the reunion, director Columbus and Radcliffe remembered the time Harris thought Fawkes, a robot, was real. 

“You and I had one of our greatest laughs together with Richard Harris. And we had an animatronic version of Fawkes the phoenix and it was this big red bird that doesn’t exist,” Columbus explained.

“It does not exist,” Radcliffe echoed.

“Richard came in and looked at the phoenix and said, ‘Wow, they train these animals marvellously these days’,” Columbus said.

Fawkes the robotic phoenix had a camera in its eye, which meant its controller had watched Harris speak to it.

“They were like, ‘Well, we don’t want to break the spell so we’ll just keep the bird reacting and moving’,” Radcliffe recalled.

7. Lots of love between Emma Watson and Tom Felton

Fans have long wondered if anything romantic has happened between the co-stars. Photo: HBO

After years of speculation from fans about whether the pair had ever dated, Watson revealed the truth during the reunion special.

The short answer is no. The long answer is still no, but there is a lot of love between them.

Watson reminisced about the time she had a crush on Felton, who is three years older than her.

She said she first developed the crush during a tutoring session when the children were asked to draw what God looked like.

“Tom had drawn a girl with a backward cap on a skateboard, and – I just don’t know how to say it – but I just fell in love with him.”

She used to come to set every day hoping to see his number on the call sheet.

“If his number was on the call sheet, it was an extra exciting day,” Watson said.

But she knew Felton only saw her as a “little sister”.

Watson explains when she first “fell in love” with Felton. Photo: HBO

“Really, the truth of it is Tom was the one I could often be more vulnerable with,” Watson explained.

She also assured viewers that nothing has ever happened romantically between them.

“We just love each other. That’s all I can say about that,” she said.

Viewers in Australia can stream Harry Potter 20th Anniversary: Return to Hogwarts on Binge.