Everything we learned from HBO Max's 'Harry Potter' reunion, from Emma Watson nearly quitting to Daniel Radcliffe's crush

The best way to ring in the new year? With secrets from the wizarding world, of course.

The Harry Potter reunion special, Harry Potter 20th Anniversary: Return to Hogwarts, dropped on HBO Max on Jan. 1, and brought together the cast and crew of the iconic fantasy franchise. Based on J.K. Rowling’s books about a boy who learns he has an extraordinary legacy in a hidden, often dangerous, and always exciting magical world, the special reviewed the experiences of bringing that world to life, from the people behind it.

The film franchise spanned a full decade — meaning there was plenty of behind-the-scenes secrets for the Harry Potter cast to unveil. Here are the most surprising moments from the special.

Emma Watson loved Tom Felton

While the brilliant Hermione and bully Draco never fell in love onscreen (just in the head cannon of many a Dramione fan) Watson always felt a deep affection for her co-star — and it stemmed from watching him do an assignment for an on-set tutor.

"The assignment that had been given was to draw what you thought God looked like, and Tom had drawn a girl with a backward cap on a skateboard,” Watson recalled. “And I just don’t know how to say it — I just fell in love with him."

Fun fact: In 2018, a backward-cap wearing Watson went skateboarding with Felton, and it’s all documented on Instagram.

Video: Emma Watson recalls moment she 'fell in love' with Tom Felton

J.K. Rowling doesn’t make an appearance

Author Rowling — who recently came under fire for making multiple comments that many people, including many Harry Potter fans, consider transphobic — does not make an appearance in the new special alongside the cast. Instead, she’s featured via older interviews.

Watson was a huge fan of the books

Watson, who was around 8 when the first Harry Potter book came out in 1998, said she was a huge fan of the books prior to being cast as Hermione. She explained in the special, “My dad used to do all the voices [while reading the book.] He would finish one chapter and we would go ‘One more, one more.’”

Chris Columbus found Daniel Radcliffe

Columbus, who made the first two Harry Potter films, found Radcliffe while watching the BBC’s version of David Coppefield. Columbus thought that the young Radcliffe would be the ideal choice for the boy wizard, but Radcliffe’s parents weren’t so sure they wanted him to participate.

“I think the deal was to sign on for seven films and it would be filmed in LA,” Radcliffe recalled. “They were like, ‘No, that’s a huge disruptor to his life.’” Eventually, a producer convinced the actor’s dad to audition — and the rest is history. The movies ended up shooting in the U.K.

Jason Isaac accidentally hit Tom Felton on set

Isaac, who portrayed Draco’s Death Eater father Lucius Malfoy, shared how, in the very first scene he filmed for the movies, he accidentally hit his onscreen son with a cane.

“Draco touched something, and I used this cane [to hit him away],” he recalled. “I didn’t know how sharp the teeth were, and they went right into little Tom’s hands. He looked up to me, eyes welled with tears, and I said ‘Tom, I’m sorry, I didn’t realize how sharp and how it heavy it was.’ And he went, ‘It’s alright, it’s good for the scene.’”

Felton joked, “He was a real Jeckyl and Hyde, he was.”

Alfonso Cuarón assigned the cast homework

Cuarón, who directed Harry Potter and the Prisoner of Azkaban, told Rupert Grint, Watson, and Radcliffe to write essays in character as preparation for shooting. While Grint didn’t turn in anything because he thought “Ron wouldn’t do it,” and Radcliffe wrote a single page, Watson penned 12 pages — a classic Hermione move.

Daniel Radcliffe sent Helena Bonham Carter a sweet note

While their characters had no love for one another on set, Radcliffe and Carter — who played the villainous Bellatrix Lastrange — shared a sweet moment in the reunion special. Carter had Radcliffe read a note he gave her on set, in which he joked about constantly having to hold her coffee — and wishing he was born “10 years earlier” lest he had “a chance” with the actress.

Emma Watson almost backed out of the franchise

Prior to filming Order of the Phoenix, Watson shared that she almost walked away from the franchise, explaining that she started feeling “lonely” in her fame. In conversation with Grint, she recalled feeling like her fame had reached a “tipping point,” and she realized her life as Hermione was “forever now.”

“The fame thing kind of hit me in a big way,” she remembered.

Ultimately, it was the encouragement of the fans and her cast and crew that made her realize she wanted to continue on in the wizarding journey.

Emma Watson had a pet hamster on set.

Watson was able to have a pet on set — something that Radcliffe admitted he was “jealous of.” Tragically, Millie the hamster died — and the carpentry department made Watson a small coffin to bury her beloved friend in.

“It had velvet on the inside of it, and it had her name engraved,” Watson said. “I was beside myself.”

Rupert Grint and Emma Watson struggled with their onscreen kiss

The franchise’s ultimate will-they-or-won’t-they couple finally kissed in the seventh film — but it took a lot of effort on the part of the actors to get there.

“It was meant to be this dramatic makeout, but we just kept laughing,” Watson said. “I didn’t think we were going to get it.”

Radcliffe admitted that he was “an absolute dick” about the kiss, because he kept joking with his already nervous friends that he was going to “come on set and watch you guys kiss.”

Watson admitted that the kiss “felt wrong on every level,” because “Dan, Rupert and I are so much siblings.”

Rupert Grint had a hard time moving on from Ron

“I feel like I lost track of who I was and who the character was. I didn't really know where they ended or began," Grint said in the special. "Even my name didn't feel like my name. I felt I only knew how to do one thing. I knew how to play Ron."

Video courtesy of NBCUniversal. For more, check out NBC.com.