With an opening scene that looks as though it could have been plucked right out of The Kroll Show, Jake (Nick Kroll) does a commercial for an upcoming product that looks like a knockoff of Google glass that he's poured all of his (and many other people's) money into. Ross Katz' first feature film not made for TV, Adult Beginners, then segues into a lavish New York launch party that also looks like a scene from The Kroll Show, specifically "Rich Dicks."
After an appropriately glossed over hiccup involving the failure of a Chinese factory to manufacture a key part for the product, Jake's empire crumbles before it can begin once news of this reaches all the tech websites. Reeking of shame and defeat, Jake retreats to New Rochelle in Westchester, where his sister, Justine (Rose Byrne, best known for her type A role in Bridesmaids), has taken over their parents' house with her own husband, Danny (Bobby Cannavale, best known for getting a blow job from Samantha Jones on Sex and the City), and their three-year-old son, Teddy (Caleb and Matthew Paddock, pulling an Olsen twins in one role).
Surprised to see Jake, so accustomed has she been to his absence and lack of interest in her life, Justine is more reluctant to let him stay with them than Danny, who suggests taking advantage of getting some child care out of the situation. Jake, though a child himself, agrees to the terms of staying with them, especially since Justine has another baby on the way and can't afford to miss any more work (she's a guidance counselor at the local high school).
Although we're supposed to infer that the premise of Jake taking responsibility for a child is naturally going to force his character to arc and imbue him with a level of maturity previously unknown, there is something decidedly hollow about his so-called transformation. The title of the film itself stems from the fact that Justine and Jake never learned how to swim as children (surely, you can see the symbolic nature of this), yet must accompany Teddy to a swim class where the teacher, Miss Jenn (Jane Krakowski, in a wasted role), suggests that the two of them take her Adult Beginners class.
After three months spent in seeming atrophy, Jake is offered a job by one of the dads of the kids he helps babysit for (he's gotten a reputation for superb nannying skills throughout New Rochelle). While Justine has assumed he's made an emotional connection to her family too lasting to leave, she chides herself for thinking that he has changed in any way--he's just as selfish as when he couldn't even be bothered to show up to the hospital when their mother was dying of cancer. But, of course, it wouldn't be a feel-good movie if this were really the case. All in all, Duplass Brothers Productions would have been better off producing a The Kroll Show Movie instead.