In 1998, not yet 30 years old, director Darren Aronofsky released *Pi*, his scrappy black-and-white debut. Clocking in at a manic 84 minutes, the film is as smart as it is darkly comedic, a feat considering nearly all those minutes are spent inside the deteriorating mind of a math genius named Max Cohen as he fumbles toward a unified theory of the universe. Even now, 25 years later, its brilliance is evidenced in its impact.

The decades have been good to *Pi*. Its happy swirl of Jewish mysticism, meaning-of-everything conspiracism, and Math’s Greatest Hits (along with pi, it bangs through the Fibonnaci sequence, the golden ratio, and Archimedes in the tub) has aged well. Each year, the concept of pi seems to grow annually in crossover popularity, via memes, novelty T-shirts, and all the attendant hoopla around Pi Day. (A personal favorite pi-in-the-culture moment: MF Doom rapping “Easy as pi, three point one four / one more one false move and you’re done for” on 2004’s “Great Day.”) So what role did the cultishly beloved *Pi* play in the growth of pi?

“I was making the movie in a very-early-internet universe,” Aronofsky says. “Information didn’t flow as obviously. You just had to hear things *from* people, learn about things *from* people. I remember when we were trying to research sacred geometry: There were only some fringe books that we had to order that took months to get to us. The Kabbalah stuff, it was before it had become part of the culture.”

Similarly, Aronofsky is aware that pi’s popularity has grown since his movie came out. “So, yeah, you always wonder,” he says. “‘Is it the film that influenced it? Or is it simultaneous with how the world is changing, and you’re sort of somehow a messenger?’”

Aronofsky and his producers raised the movie’s budget a hundred US dollars at a time, effectively using the now internet-beloved technique of crowdfunding long before that was a familiar term. “It was a form letter,” Aronofsky says. “I still remember the opening: ‘Yes, this is a form letter, but it’s not because we don’t love you.’” They offered a return of $150 (£123), two tickets to the premiere, and a name in the credits—if the movie was ever made, of course. “The people we were writing to, they probably thought we were out of our minds,” he says.

Since its release, *Pi* has become a touchstone for the math obsessed. “There are so many people from Silicon Valley that *Pi* was an important film for,” Aronofsky says. “You know, they were the nerdy kids doing math and suddenly there was this movie that was showing how mind-expansive math can be. Jack Dorsey told me once that, as a teenage boy, it made math cool.”

It’s pretty much impossible to quantify, but anecdotally, *Pi* the movie has seemed to naturally fuel π the concept. It came a decade after the original Pi Day, which was started at the Exploratorium, San Francisco’s learning center dedicated to “science, art, and human perception.” Sam Sharkland, the center’s senior program director, says that *Pi*’s “promise of somehow making sense out of something that almost defines randomness is alluring.” Both Pi Day and the movie give meaning to “concepts that are hard to wrap our head around,” he says, adding that the movie “puts pi in the spotlight, elevating it beyond its simple function in geometric, grade school calculations.”

But it’s not just the film and Pi Day that have raised cultural awareness of 3.14159265359. As Ursula Whitcher, an associate editor at *Mathematical Reviews*, the journal of the American Mathematical Society, notes, it’s possible pi’s popularity “owes much more to the deliciousness of pie” than it does to anything else, referencing the long-running tradition of baking to celebrate the mathematical constant.

Additionally, *Pi*’s underlying rigorousness in its treatment of math concepts can leave some viewers less than satisfied. The 2012 book *Math Goes to the Movies* points out a few huge goofs, including the title sequence’s misrepresentation of pi’s decimal expansion. Representative quote: “All that Max says here is basically nonsense.”