Comedian Mike Birbiglia has gained acclaim and popularity through his anecdotes about struggling with REM behavior disorder. His one-man show, Sleepwalk with Me, made him a finalist for the Thurber prize, and his same-title memoir was a best-seller. Now, he’s again getting mileage out of his autobiographical details, having directed, written, and starred in a cinematic version of his travails with sleepwalking. The movie Sleepwalk with Me showcases everything that makes Birbiglia a great comic: his sheepish relatability and wry observational sense. It’s a winner, funny and affecting in equal measure.

Unlike the show and book, this is a fictionalized account of Birbiglia’s experiences. He stars as Matt Pandamiglio, an amateur stand-up struggling with both his work and his relationship with his longtime girlfriend, Abby (Lauren Ambrose). Abby feels herself increasingly drawn towards marriage, while Matt finds the idea anathema. As stress builds in his life, Matt finds himself acting out his dreams in real life as he sleeps, leading to more than one rather dangerous situation. The problem is only exacerbated when Matt’s career begins to take off, and he finds himself bedding at odd hours in strange motel rooms. The more he avoids dealing with his problems, the worse the sleepwalking gets.

The movie comes from the producers of This American Life, and it’s very much in line with the sensibilities of that program (Birbiglia also performed an abridged version of Sleepwalk for one of the episodes, meaning that this is the fourth iteration of the story). Everything about it is very low-key; there are few huge punchlines or “big” moments. The humor comes from situational irony and small lines and actions. It’s not aiming for belly laughs but consistent chuckles, and it does so extremely well. Much of the humor comes from Birbiglia addressing the audience as his own Greek chorus (as someone who’s heard the show, it’s hard to imagine the story playing out without his narration). Often, he’ll comment directly on the conventions of genre, such as pointing out that the audience is still meant to be on his side when he does something less-than-honorable.

Which is unnecessary, since Matt isn’t a hard character to root for. Which is somewhat remarkable, given that the whole plot revolves around him studiously attempting to avoid commitment, responsibility, and most other aspects of becoming a functional adult. It works because Birbiglia makes him hugely likable. As Abby, Lauren Ambrose is also rather terrific. Although her role in the story is to prod Matt towards marriage, she has far more dimensions to her than simply being obsessed with matrimony. That sense of full characterization extends to the supporting cast as well, which includes James Rebhorn and Carol Kane as Matt’s parents. These people feel lived-in within the world of the movie. Additionally, a cavalcade of comics have cameos, including Marc Maron, Wyatt Cenac, and Kristen Schaal. They appear only briefly, but they’re all memorable.

The realism is most apparent in the dream sequences. Movies (really, most media) almost always get dreaming wrong. Dreams aren’t magnificent and laden with obvious symbolism – they’re weird and random and often quite mundane. That’s what this film understands. Matt’s sleepwalking doesn’t involve acting out imagined action scenes. He runs a marathon through a field, and wins a bouquet with a baby in it for third place. That’s true-to-life, and all the funnier for it.

Sleepwalk with Me is a lovely little movie. Birbiglia’s observations about relationships, family, honing one’s creative abilities, and life in general all ring close to home. It’s gentle, somewhat philosophical side is balanced with a great sense of wit and good fun. Occasionally, Birbiglia’s weaknesses as a first-time director are evident, such as spaces when the plot sort of flounders, but it’s overall very accomplished. Whether or not you’re a fan of This American Life (although if you aren’t, what’s wrong with you?), you’ll probably like this movie.