He comes of age in a water park

I recall reading somewhere that a single caring adult can alter the whole trajectory of a kid's life, particularly if that adult shows up at a critical point in a young person's development.

I thought about that while watching The Way, Way Back, a comedy about a dejected, angry teen-ager who blossoms under the mentorship of the owner of a Massachusetts water park called Water Wizz.

Fourteen-year-old Duncan (Liam James) seems entirely uncomfortable in the world until he meets Owen (Sam Rockwell), an adult who senses the boy's loneliness and encourages him have a little fun.

For Duncan, loosening-up is no easy task. He's stuck on a month-long beach vacation with his divorced mother (Toni Collette) and the new man in her life (Steve Carell). To make matters even worse, Carell's Trent and Collette's Pam are in the early stages of their relationship and have yet to settle important territorial issues.

Just to add a little more insult to the already festering pile of Duncan's injuries, Trent's daugther (Zoe Levin) is a stuck-up, socially conscious teen who's totally condescending toward the dweebish Duncan -- at least when she's not entirely indifferent toward what she perceives as his worthless existence.

Directed and written by Nat Faxon and Jim Rash -- actors and screenwriters who won an Oscar for adapting The Descendants for the screen -- The Way, Way Back can't entirely overcome the familiarity of what amounts to yet another teen reclamation project. But the movie offers interesting wrinkles en route to a predictable -- if slightly attenuated -- finale.

To begin with, The Way, Way Back allows Carell to play to a jerk. Carell's Trent declares his jerkhood from the movie's outset, and does little to change our opinion of him as the story develops.

In Pam, Trent seems to have found a woman so desperate to hold onto a potentially stable relationship that she'll put up with a lot. Trent seems more than willing to take advantage of the situation. He shows far more interest in socializing with another couple (Rob Corddry and Amanda Peet) than in testing the waters of stepfatherhood -- or even in spending time with Pam.

Duncan's shot at self-affirmation arrives in the form of Rockwell's Owen, who becomes a kind of surrogate father for Owen. Not only does Owen offer Duncan a job at Water Wizz, he knows how to relate to a kid, in part because he still is one. In a way, the movie is Owen's coming-of-age story, too.

The cast is further bolstered by Allison Janney, who plays Trent's garrulous neighbor and Anna Sophia Robb, who appears as Janney's daughter, a girl who's smart enough to take an interest in the dejected Duncan, who suffers one indignity after another. An example: He's forced to explore the beachfront Massachusetts town where the story unfolds on a pink girls' bicycle he finds in Trent's garage.

Maya Rudloph appears as one of Sam's employees, and both Faxon and Rash play small roles as water-park workers.

To their credit, Faxon and Rash provide some shading, even for the dislikable Trent, and they belatedly give Collette a chance to dig more deeply into a character with an alarming tendency toward over-dependence.

For all of this, The Way, Way Back may leave you shrugging, perhaps because we've been down this road too many times, perhaps because the movie tends to be a bit bland and perhaps because the adult conflicts -- though sketchily presented -- are more interesting than Duncan's problems.

Let me backtrack a bit, though. It's convenient, but a little inaccurate to classify The Way, Way Back as a coming-of-age story. In truth, neither the movie's teens nor its adults fully mature.

Rather, they're brought to the brink of important life changes. Faxon and Rash keep the movie's ending upbeat, but allow us just enough room to speculate about whether these characters really will be able to sustain new and better versions of themselves.