Everyone carries around the baggage of personal experience. At best, it’s distilled into a handy guidebook, available for reference as needed, and light enough not to weigh down the bearer.

With its references to time-travel, mental instability, the pangs of lost love, and the possibilities of romantic adventure, Safety Not Guaranteed starts by strapping itself down to routine expectations. And if the viewer is familiar with lead actors Aubrey Plaza, Mark Duplass, and Jake Johnson from their other creative endeavors, the combined weight could prove to be a serious drag.

In the genial atmosphere created by writer Derek Connolly and director Colin Trevorrow, however, a strange chemical reaction occurs, and the result is not at all according to formula; the baggage is cut loose and the characters float upward, if not quite into the stratosphere. Safety Not Guaranteed is amiable, lovable, adorable, and winning.

The humor is silly, broad, and varied; mostly it consists of one-liners delivered in a familiar, deadpan rhythm: boom, chicka-chicka boom, seasoned by visual jokes and carefully-observed, well-timed facial reactions. Some of it erupts, no doubt, from familiarity with the performers; if you’ve watched Parks and Recreation and/or New Girl during the past broadcast television season(s), then you’ve been indoctrinated into the sly style of humor practiced by Plaza and Johnson; if you’ve seen any other movie in which Duplass has acted, you can pretty much anticipate his every move.

Perhaps my familiarity with Plaza and Johnson — especiall Plaza, who has blossomed into a more versatile performer in the last year and displayed a wider range on TV than shown here — makes me more susceptible to the humor, which I found to be sly and clever. As someone who is allergic to broad, studio-system comedies that aim at the lowest common denominator, Safety Not Guaranteed is, happily, not that. It’s much smarter, aiming at the heart rather than the belly or the groin.

Darius (Plaza) is an intern for Seattle Magazine who desperately wants a break; Jeff (Johnson) is a complacent staff writer. When an unusual classified ad catches the attention of the magazine’s editor at a pitch meeting, Jeff grabs the out-of-town assignment and requests two interns for assistance. Darius quickly volunteers, as does the prototypical nerdy Amau (Karan Soni).

Soon it’s revealed that Jeff is only interested in the assignment because he wants to reunite with high school love Liz (Jenica Bergere), who lives in town. While he tries to spark up old romantic fires, Darius is left to investigate the individual who advertised for a companion to “go back in time.” When she makes contact with Kenneth Calloway (Duplass), he appears to be a delusional paranoid who works at a grocery store, a basically harmless type who charms her without necessarily meaning to do so, even as he sounds and acts more and more unhinged.

Darius pretends to take Kenneth (and his claims to have built a time machine) seriously so she can get a story for the magazine, but soon finds herself falling for him. Other than the secrets that he harbors, he is an open and honest person, friendly to a point and pretty adorable to someone like Darius, who has built a self-protective shell around herself.

Meanwhile, Jeff pursues Liz with a clear agenda set in his own mind. Most obviously, he wants to time travel in the emotional sense, to go back to a period when the world was simpler and, he and Liz enjoyed a pure love, unhindred by real-life (i.e., adult) responsibilities.

While these emotional currents are swirling quite obviously below the surface — as though the emotional lives of the characters were covered only in a thin layer of transparent material — the story moves forward and the humor keeps flowing in an agreeable manner.

No one hides in Safety Not Guaranteed; not really. The characters plainly lay bare their attributes and flaws to those they care about the most, sometimes without even realizing it, all of which helps to make the film a rousing success.

Safety Not Guaranteed opens today at Angelika Dallas and Cinemark West Plano.

Originally published, in slightly different form, at Twitch. Photos courtesy of FilmDistrict and Big Beach.