Based on Peter Cameron's novel and operating like the unholy spawn of Tadpole and Waiting for Forever, the twee-tastically titled Someday This Pain Will Be Useful to You charts the oh-so-precious coming of age of a 17-year-old twerp named James (Toby Regbo), whose life of privilege and lack of responsibilities is so sad and difficult that, per genre cliché, he opens Roberto Faenza's film perched on the edge of his apartment building rooftop, contemplating suicide. Alas, no swan dive to the asphalt follows, meaning we're forced to endure his subsequent saga of self-actualization, which involves a cast of characters each more grating than the last.
There's mom Marjorie (Marcia Gay Harden), mourning the collapse of her latest marriage—this one to gambling addict Barry (Stephen Lang)—as she runs an art gallery noted for its installation of smoking trash cans that make weird noises when their lids are lifted. There's also sister Gillian (Deborah Ann Woll), who's dating her married professor and wants her name to be pronounced with a hard "G." And don't forget grandma Nanette (Ellen Burstyn), who enables James's self-absorbed dreams of being a "tradesman," and cosmetic surgery-loving narcissist dad Paul (Peter Gallagher), who objects to James's desire to skip college, a downy-soft sensitive life coach played by Lucy Liu, and Aubrey Plaza's real estate agent, who shows up to merely add further kookiness to proceedings already oozing obnoxiousness.
Faenza shoots his Manhattan-set action with a glossiness that's as bland as the soundtrack ballads, but it's the script that truly drives the film into a mushy pit of pretentiousness. James commences things with "I wish the whole day was like breakfast, when people are still connected to their dreams," and things go steeply downhill from there, what with everyone discussing whether James is "normal," "antisocial," disturbed," or "lonely," all as James himself laments the fact that everyone in New York has a rhythm but him, because "All I hear is silence."
Amid its protagonist's overly verbose ruminations on his own navel, the story finds James reminiscing about a traumatic school experience in Washington D.C., and playing a prank on a gallery programmer that quite obviously suggests he's gay, even though he refuses to admit that to his dad, and the film attempts to play coy about it for reasons that make no sense whatsoever—except, of course, because the real focus isn't on James as a person, but as a sort of brooding, WASP-y Gap model. Given dreadful material, no one in the cast does even passable work; it's just a roundelay of dysfunction, which the film trots out as a cool affectation that's easily overcome by, well, by having others die so you can gain perspective.