Megan Park on ‘My Old Ass’ Movie With Maisy Stella and Aubrey Plaza

“The Fallout” director Megan Park began working on her second feature with a vague concept and bold title: “My Old Ass.”

“The title was one of the first things that I came up with,” Park says of the film, which was released in theaters Friday. “I didn’t know where the story was going to go or what was going to happen necessarily — but the title, it set the tone for me.”

It’s mid-August, and the 38-year-old writer-director is in New York for press, including an outdoor screening of the film later that evening on the downtown waterfront. “My Old Ass” premiered during the Sundance Film Festival earlier this year, and is getting a theatrical release nine months later, just as summer begins its transition to fall.  

“It feels like a really good time of year for it to come out,” says Park of the release date. The film takes place during the summer before the main character heads off to their freshman year of college. “That was our dream.”

While selling the movie, the title became a litmus test, one that Amazon and MGM passed. “People who got the movie understood the title,” Park says. “And once we were at Amazon, it was never a question. They were like, yeah — this is the title.”

The film was produced by Margot Robbie’s LuckyChap production company. An executive reached out after watching Park’s debut feature “The Fallout,” which premiered at SXSW, and asked if she was working on anything else. Park relayed that she was working on a story about a mushroom trip, with a dual old-young main character.  

“The mushrooms [plot] was secondary to the idea of, how do you answer the question ‘what advice would you give your younger self?’” Park says. 

The coming-of-age film is led by Maisy Stella and Aubrey Plaza, who portray the same character, Elliott, at different ages. Elliott meets her older self — “my old ass,” as she affectionately calls her — during a psychedelic mushroom trip on her 18th birthday. The relationship continues as older-Elliott becomes a surrogate older sister, offering advice with the wisdom of hindsight. “It leaves you with this feeling of, was it real or was it not?” Park says of the initial setup. 

Park found her younger lead in newcomer Stella, who she met during the casting process for “The Fallout.” (Stella, who’s also a musician, ended up writing and recording a song for the film with her sister, Lennon.) 

“I find that a lot of young performers, it’s almost like they’re pretending to be young people. They’re so jaded,” Park says. “She just has this sparkle and this freshness and this real grounded-ness to her that’s quite hard to find and capture.”

For Elliott’s older counterpart, Park looked outside the realm of physical look-a-likes and cast Aubrey Plaza. “We got to a point where I was like, ‘Who do I want to see in this movie when the camera pans over?’” Park says. “The fact that they don’t look alike, it just adds to the comedy.” Also, “If you don’t buy in and you get caught up in the logistics, we haven’t done our job,” Park adds.

The film is set in the idyllic Muskoka in Ontario, a popular lakeside vacation destination not far from Toronto. Park and Stella — who are both Canadian — both spent childhood summers in the area, adding to the nostalgic appeal. 

“The producers were like, where is this place you keep talking about? Let’s go there and see if we can make it there. Which was tricky, but still worth it,” says Park, adding that filming on-location set the for production. “Everybody was staying in cabins on the lake — we picked Aubrey up for dinner in a paddleboat,” she adds. “We all had anklets — all the producers, the actors — it was like summer camp.”

Park and the filmmaking team took a chance on a memorable scene towards the end of the film, which features a trippy performance of Justin Bieber’s “One Less Lonely Girl.” Park had asked her Gen Z cast to name an iconic musical moment from their era — enter Bieber — and then shot the scene, knowing that they’d only be able to get approval from the musician afterward. 

“We had to shoot it knowing that we might not be able to use it. Which would have been such a bummer,” Park says. Luckily, Bieber’s team approved. “I mean, how could you not? I feel like he gets it. He’s a Canadian kid.”

Park began her career as an actress, starring on the popular series “The Secret Life of the American Teenager,” before pivoting her focus to behind the camera. “I got this master class being on set — being comfortable and working with actors — without going to film school,” says Park, who’s currently working on “a couple of things” too early to discuss.

As for the release of “My Old Ass,” Park is thrilled that the film has appealed to viewers across generations. 

“What’s been so interesting about the takeaways, and sitting in on the test screenings, is hearing the feedback of what the 18-year-olds are taking away from it, versus 40-year-olds. It’s all in the same vein, but in different ways,” she says. “The best compliment I get is ‘I stepped out of the theater and I called my mom and my dad.’ That’s the ultimate feeling.”