There’s something inherently formulaic about summer coming-of-age movies. A quirky, awkward and misunderstood kid takes a summer off from regular life and finds a way — at the beach or by the pool — to, well, come of age, often with the help of an equally quirky adult. Summer ends. Life is changed.

And that’s precisely what happens in “The Way, Way Back,” featuring an expert cast led by Steve Carell, Toni Collette and the terrific Sam Rockwell as that quirky adult.

Luckily, though, the film, written and directed by Nat Faxon and Jim Rash, is done with enough skill and delicacy that its adherence to formula doesn’t matter quite so much.

About that title: “The Way, Way Back” refers to the back seat in a station wagon that faces out to the road — the way, WAY back seat.

Which is where 14-year-old Duncan, played by sensitive newcomer Liam James, sits as he reluctantly heads for a beach vacation with his divorced mom Pam (Collette) and her boyfriend, Trent.

The first scene tells you all you need to know about Trent, a very unlikable character played by the very likable Carell. At the wheel next to Duncan’s sleeping mom, he barks a question to the teenager: How would you rate yourself, on a scale of 10? When Duncan hazards a weak “six,” Trent replies that in his view, the boy’s a mere three.

It takes a while for Pam to notice her beau’s shortcomings. Meantime, Duncan is trying to find a way to pass the time. He grabs a pink girl’s bike from the yard and heads to the Water Wizz water park.

There he finds park manager Owen (Rockwell, in the film’s most entertaining performance), a guy he’s met briefly in town. Owen is not too responsible, but full of fun and armed with a wisecrack for any occasion. He gives Duncan a job and sets about removing the boy from his shell.

Also noteworthy here: Allison Janney as a neighbor with an absurdly dark tan, a taste for cocktails and a way-too-loose tongue; Amanda Peet and Rob Corddry as Trent’s married, fun-loving friends; and AnnaSophia Robb as a romantic interest for Duncan.

Will Duncan learn about himself as the summer progresses? Will he overcome obstacles to his self-esteem? Take a guess. Luckily, the ending is less predictable and sappy than it could have been.

And actually, “The Way, Way Back” feels something like summer itself: It meanders a bit, it’s a little lacking in structure, but it’s full of small memorable moments — and you’re sad when it’s over.