The Harry Potter Cast Take a Magical Trip Down Memory Lane in the Return to Hogwarts Special

Settled in cosy common rooms with glasses of Champagne, Radcliffe, Watson, and Grint reminisced about their wizarding days and how filming the Harry Potter series was a formative experience in their lives.

"I think I probably would have been about 8 years old when the first one came out," Watson said. "[Reading the books] became our family thing. My dad used to do all the voices, and my brother and I just became obsessed. We would just beg him to keep going, and every time he'd finish a chapter, we'd be like, 'One more, one more, please.'"

For The Boy Who Lived, the role was practically foreseen in Professor Trelawney's crystal ball. While thousands showed up to audition as Harry Potter, Radcliffe's parents believed the role would be too big of a disruption in his life. "I was a really happy kid who had a really haunted quality, apparently," Radcliffe said. After seeing the then 10-year-old's work in David Copperfield (1999), producer David Heyman convinced Radcliffe's father to bring him in for an audition, and the Chosen One was born.

To add to the nostalgia, actors including Tom Felton, James Phelps, Oliver Phelps, Matthew Lewis, Alfred Enoch, Bonnie Wright, and Evanna Lynch shared their own stories about their time on set. Between nostalgic never-before-seen photos of the actors as children, behind-the-scenes footage of the cast revealed how difficult it was for them to acclimate to the overwhelming fame associated with being in the Harry Potter films.

At the start of the franchise, the 11-year-old actors couldn't even go home because their houses were swarmed with adoring fans and paparazzi. But working with directors like Chris Columbus, who directed The Sorcerer's Stone and The Chamber of Secrets, created a lighthearted environment for the young actors behind the scenes and made work feel like playtime.

"Obviously, we were just kids, and we were all looking forward to mucking about together," Felton said. "Chris Columbus made the atmosphere very much like a fun-fair." Radcliffe added, "We were very much just kids being kids on a set. They probably made their jobs harder for themselves by letting us have as much fun as we had because it distracted us from the work we were supposed to be doing."

Reflecting on their teenage years, Watson and Radcliffe revealed that they used to give each other advice on texting and flirting with their crushes when they were 15. But one thing we didn't need the Return to Hogwarts special to know is that, despite their onscreen hatred for each other, Watson and Tom Felton have always been one of the most-shipped couples in the Harry Potter fandom. Speaking on the rumours, Felton said, "I think I was in the hair and makeup chair and someone said something along the lines of, 'Yeah, [Watson] had a crush on you.'"

Once the camera turned to Watson, the actor smiled and added, "I used to come in every day and look for [Felton's] number on the call sheet. It was number seven. And if his number was on the call sheet, it was an extra exciting day. [But] he was three years above me, and so for him, he was like, 'You're like my little sister.' Really, the truth of it, was that Tom was the one that I could often be more vulnerable with. Nothing has ever, ever, ever, ever happened romantically with us. We just love each other. That's all I can say about that."

For Felton, the platonic love for his costar remains strong. "I became very protective of her," he said. "Yeah, I've always had a soft spot for her, and that continues to the day."

Watson wasn't the only one with an unsuspecting crush. It turns out Radcliffe had taken quite the liking to Helena Bonham Carter, who is 23 years older than him. During the Return to Hogwarts reunion, Carter pulled out a picture of a letter Radcliffe wrote to her and autographed when he was younger.

The titular Harry Potter star read it aloud and seemingly got embarrassed as his crush was revealed. "Dear HBC, it was a pleasure being your costar and coaster, in the sense that I always ended up holding your coffee," the letter began. "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." Carter said she treasured the letter, jokingly adding, "That is in my toilet, Dan."

Ahead of filming The Order of the Phoenix, Watson considered pulling out of the franchise because she began to feel scared and lonely being burdened with so much fame at such a young age. "The fame thing finally hit home in a big way," she said, recalling old diary entries that shed a light on her feelings of loneliness at the time. "[But] no one had to convince me to see it through. The fans genuinely wanted us to succeed, and we all genuinely had each other's backs."

When the franchise first started filming in 2000, many of the special effects that made the wizarding world feel so magical were done using strings, wires, and wind machines, rather than the CGI we're familiar with today, which had its ups and downs. "One of my favourite moments on set was the moment when all the floating candles started burning through the ropes that tied them to the ceiling and just started falling around the great hall," Radcliffe recalled before Watson added, "Hundreds of real candles that were really lit on fishing line from the ceiling."

When CGI became more popular, effects like Voldemort's reptilian nose, which was created using special-effects stickers rather than makeup, became even spookier on screen. Later on, the special effects were so realistic that they even fooled actors like Richard Harris, aka Dumbledore, who fully believed that the animatronic of Fawkes the phoenix was a real bird.

Other fun Harry Potter trivia to keep in mind:

• James Phelps accidentally cracked director Mike Newell's rib during a fight scene on set for The Goblet of Fire.
• Watson fell down the stairs during Hermione's dress-reveal scene at the Yule Ball.
• Maggie Smith chose Grint to dance with her during the Yule Ball rehearsal, and the rest of the scene was ad-libbed.
• No one, including the directors, knew ahead of time what would happen to their characters, except Alan Rickman, who convinced Rowling to tell him about Snape's fate.
• Jason Isaacs, aka Lucius Malfoy, originally auditioned for the role of Gilderoy Lockhart. After being asked to read for Malfoy, Isaacs read his lines so bitterly that there was no contest for who should play Draco's father.
• In a deleted scene, Isaacs accidentally cut Felton with the teeth of his walking stick. "I went, 'Tom, I'm so sorry, I didn't realise how sharp they were and how heavy it was,'" Isaacs said, "And he [tearfully] went, 'No, no, it's all right. It was good for the scene.'" Felton jokingly added, "He'd be this evil father and then they'd say 'Cut!' and he'd come and give you a cuddle."

Beyond the fame and acting experience they gained, the cast are most grateful for their memories with one another. Together, the cast built a family consisting of new actors and British film royalty, including Richard Harris, Maggie Smith, Richard Griffiths, Kenneth Branagh, Timothy Spall, and Robbie Coltrane.

"[Richard Griffiths's] passing was the one that has affected me most because he was generous with knowledge and just wanted to share everything with you," Radcliffe said of the late actor ahead of a tribute section that paid homage to late Harry Potter stars like Helen McCrory, Alan Rickman, and John Hurt.

For the remaining cast, the families they've built on set continue to hold a special place in their hearts even 10 years after the final Harry Potter film's debut. "I feel like being a Weasley is the best part of being in Harry Potter," Bonnie Wright said. "We had our Hogwarts family, but I felt so special having an actual extra family . . . Julie Walters, who played my mother, Mrs. Weasley, was just so wonderful and brilliant to me. She really kind of took me under her wing, and she was like the perfect mother figure."

Over the course of a decade, the films gave the cast a space where everyone belonged and everyone could be themselves, making the franchise just as valuable to the cast as it is to its fans. "There's something about Harry Potter that makes life richer," Watson said. "When things get really dark and times are really hard, stories give us places we can go where we can rest and feel held."