“The title was a helpful reminder not to get too mushy”: Filmmaker Megan Park on her new Muskoka-set movie, My Old Ass

My Old Ass is a time-travel dramedy in the grand tradition of 13 Going On 30 and Seventeen Again—only with a Muskoka backdrop, magic mushrooms and a gender-reverse Justin Bieber hallucination sequence that was approved by Team Biebs. Writer-director Megan Park grew up in Lindsay, Ontario, and spent her summers on the lake. The movie, which stars Aubrey Plaza (Parks and Rec, The White Lotus) and Oshawa’s Maisy Stella (Nashville) as the older and younger versions of the same character, is both a nostalgic love letter to and a contemporary reworking of the classic coming-of-age tale—and it’s already getting some Oscar buzz. Here, Park talks to Toronto Life about filming in Muskoka, working with producer Margot Robbie and her movie’s spicy title.

I understand that the idea for this movie came to you while you were spending the night in your childhood bedroom. I was staying at my childhood home during the pandemic. I had just given birth to my daughter, and I was sleeping in my old bedroom. What I started thinking about ended up being a scene in the movie, where the characters talk about how you have these last times that you’re not aware of as they’re happening: the last time you play with a certain group of friends, the last time your family sleeps under one roof before a sibling goes off to school. Maybe it was being a new mom, but the passing of time had become my worst enemy, and that made me feel really sad and nostalgic. At the same time, I had just spent two years making The Fallout, which is about the aftermath of a school shooting, so I wanted to be in a lighter headspace. I thought, How do I tap into these themes in a way that isn’t so heavy? 

The film feels like a homage to a certain kind of coming-of-age movie. Were you inspired by the stories you grew up with? Oh, definitely—My Girl, Now and Then. Those are major comfort movies that I always go back to. But I wasn’t trying to make a coming-of-age story. It was more about the idea of how we change at so many different points in life. It also came from the desire to make a heartfelt movie. There’s this idea that being heartfelt isn’t cool, but I think it is. I reference Chris Columbus movies a lot, like Mrs. Doubtfire, where he toes the line between making you laugh and making you cry and telling these beautiful stories.

But then you gave it an extremely spicy title. Was that dissonance intentional? The title was definitely a north star. I started this project with a title page, which I don’t normally do. I wanted to make something that felt contemporary and not too sentimental, so the title was a helpful reminder of that when I would start to get a bit heavy-handed or mushy.

The magic mushroom scenes helped keep things edgy. Was the idea to have a character time-travel via a shroom trip also there from the beginning? That came later. I knew I wanted to explore this question: If you could go back in time and tell something to your younger self, would you? And would your younger self want to know? There’s this question about which one of you is learning a lesson at the end of the day. It was an insane idea, so I wanted to come up with a storytelling device that felt very grounded, and the answer was magic mushrooms. I really believe that an 18-year-old would be up in Muskoka celebrating their birthday by going camping and doing mushrooms. It also leaves the audience wondering, Did that actually happen?

You sometimes hear about movies with risqué titles facing pressure to come up with a PG alternative. Did that happen to you? Only early on. When we were deciding if we were going to make the movie independently or with a studio, we met with some executives who were like, “We love it, but obviously the title has to change.” The title ended up being a good litmus test to see who understood what the movie was. For the producer and the financiers that we ended up working with, it was never an issue. It makes sense when you read the script.

Margot Robbie is one of your producers. Did you work with her before or after the explosion of Barbie? Margot and her team were with us from the beginning. I met with them after The Fallout and told them about what was then a very vague idea for my next project. They loved it, and they developed it with me, which was amazing. There was some overlap—we had some meetings with Margot when she was in her trailer on the Barbie set. And then she would be up in Muskoka, going back and forth with her husband to the set of Saltburn, which they were also producing at the time.

The Muskoka setting is so important to the movie. Was filming there a must for you? Definitely. I wrote the movie inspired by this specific place in Muskoka where I spent summers growing up and went to camp. I have so many memories: getting in the boat to go to the marina for snacks and bringing them back to the dock to eat. It’s such a special place, and one of the things I want to do as a Canadian filmmaker is tell Canadian stories. I was lucky that Margot and her team were totally supportive. They never tried to find an alternative that was less expensive. They said, “This is the place that is so important to you and so special. This is where we’ll do it.”

Where did you all stay? People stayed in different cottages, and we would literally boat to one another’s places for dinner. We filmed primarily on Lake Joe. It was great. It was like summer camp.

The main character, Elliott, can’t wait to get out of her small town and move to Toronto. You grew up in Lindsay. Did you feel the same way? That part wasn’t my story. I moved to LA when I was younger for acting jobs, but I was the kid who didn’t want to leave home and didn’t get my driver’s licence until I was older. There’s definitely a part of me in Elliott and in every character, but in this story I think I mostly related to the mom.

Does that mean the Bieber-themed mushroom sequence isn’t autobiographical? Ha, it’s not. I’d written something else for that scene—a play on a Disney song—and we couldn’t get it cleared because of the drugs. So I asked Maisy what that same touchstone for her generation would be, and she said, “Being chosen as the ‘one less lonely girl’ by Justin Bieber.”

And you got Bieber’s permission? Not until after we filmed the scene, which was nerve-racking. His team approved the script pages, but they wanted to see the cut too. I don’t know if Justin himself has seen it, but someone on his team gave us the thumbs up.

This interview has been edited for length and clarity.