Liam James learned something playing the role.
"I can relate to a lot of the things Duncan was going through," said James. "You have be yourself and have confidence that people are going to like you for you and you're going to find the right people for you."
In the film, Duncan finds some solace when he takes a job at the local water park and one of the workers, played by Sam Rockwell, takes him under his wing.
"Maybe he sees something in the kid that he experienced as a kid and he sees potential in him. And it becomes his mission to kind of bust him out of his shell a little bit," said Rockwell.
Steve Carell plays Duncan's mother's not-so-nice boyfriend.
"I was sort of an awkward kid as well. It's just a transitional period for anyone, but especially for a kid at that age, it's tough," said Carell. "You've got one foot in childhood and one foot in adulthood and you are trying to navigate that and it's dicey."
Allison Janney is also a part of the fun of this film from co-writers and co-directors Nat Faxon and Jim Rash. She plays a mom who's a bit of a mess.
"Jim and Nat gave me the best piece of direction. They told me to treat him as if he was my husband of, you know, 14 years, instead of my son. And so we had that old married couple relationship," said Janney.
"The Way, Way Back" is in limited release now. It's rated PG-13.