In a 2022 interview with Filmmaker Magazine, Jane Schoenbrun spoke about the origins of the New Year's Eve scene: "I filmed that on a camcorder. I made my partner drive with me upstate, and we spent New Year's bumming around Saugerties quietly, mapping out the path and figuring out exactly how to time it so that I could start filming at 11:57 and hit the center of town right as the countdown actually began. It really was this 'You get one shot' sort of deal.
I had gone to an Airbnb up in Saugerties over New Year's a couple years earlier. I was sick as a dog, spent that entire weekend lying around feeling terrible and didn't leave this Airbnb for three days except at midnight. I staggered out, went to the town and saw this very charming, small-town version of the Times Square ball drop. After I saw that, I was like, 'I need to work that into a movie someday.' The idea that Casey would be there filming was one of the early ideas for this film. The loneliness of being in a crowd of people and feeling like you can say whatever you want because no one is listening, or is even aware you're there, is a big part of that scene. Also, so many of the kids hanging around half a block away from the center of that party we were filming WERE Casey. It was like, 'Oh yeah, there are Caseys EVERYWHERE in towns like this.'"
The t-shirt Casey is wearing at the beginning of the movie--and in several subsequent scenes--is for the band Skullshitter, a metal band from New York City.