There are few characters in literature whose names have become a kind of shorthand. If someone is a fantasist with grandiose daydreams, you might call them a Walter Mitty, based on the 1939 short story by James Thurber. Now Ben Stiller has taken on Mitty — it’s the fourth movie he’s both directed and starred in.

Stiller’s Walter is a quiet, middle-aged man who works at the soon-to-be-shuttered LIFE magazine. “He’s just an ordinary guy,” Stiller tells Kurt Andersen, “a guy who hasn’t connected with his potential, his idea of who he wanted to be in his life. He got sidetracked by real life responsibilities.” Walter’s daydreams transform Walter into an Arctic adventurer, a swarthy romeo, and an action hero who dives into a burning building to rescue the dog of his work crush (played by Kristen Wiig). But before he can win her love, Walter sets off on a real-life adventure that challenges him to become the person he imagines himself to be.

At one point, the adventure sends Walter careening down a mountain on a skateboard, a stunt Stiller took on himself. He relied on a lone safety wire, in case the whole operation went south. “It happened a couple of times,” he tells Kurt Andersen. “I was pulled up off the skateboard and dangling like a marionette going 40 miles an hour.”

Stiller has been making movie parodies like the ones in Mitty for decades — from the fake trailers in Tropic Thunder, back to the sketches on The Ben Stiller Show, the beloved, short-running TV series he made with Judd Apatow. His first feature was Reality Bites, the coming-of-age story of recent college grads. Stiller also starred opposite Winona Rider as her corporate boyfriend. In a pivotal scene, his character warns her that it’s impossible to live by idealistic creeds. We're meant to reject that cynicism, but 20 years later, the irony isn’t lost on Stiller. His Walter is determined to live by LIFE’s (fictional) motto: “To see things thousands of miles away, things hidden behind walls and within rooms, things dangerous to come to, to draw closer, to see and be amazed.”