Compared to the talking toys of Toy Story or the separated father-and-son fish adventure in Finding Nemo, Pixar's latest movie is a colossus of a concept.
Set in the mind of an 11-year-old girl called Riley, it is terrain that would give many therapists a headache. The main characters of Inside Out – Joy, Fear, Anger, Disgust and Sadness – are all emotions that live within the youngster's head.
"When I read it – and I think of myself as an imaginative person – I didn't understand it at all," says Mindy Kaling, the star of TV hits The Mindy Project and The Office, who voices the character of Disgust.
She's not the only one. Conceived and co-directed by Pete Docter, the brains behind Pixar's Oscar-winning 2009 film Up, it took a long time before even his colleagues began to get it.
“The first year, as I would explain it to people, it was really split down the middle,” he says. “Fifty per cent of people would go: ‘Oh, cool!’ And the other half, you could see it in their eyes … they’d be going: ‘Are you crazy?’ People either got it immediately or they didn’t get it at all.”
It’s understandable, given the task of visualising the workings of the mind, rather than the physical brain itself.
“The fun thing with that is, we can go to abstract thought or the subconscious, which for me are much more interesting, as an animation guy,” says Docter.
The result is like a hallucinogenic playground, housing areas such as Personality Islands (which store all of Riley’s character traits) and the offbeat Imagination Land, all linked by the high-speed Train of Thought.
The story kicks off when Riley’s parents move from an idyllic rural home to San Francisco, a traumatic moment that sends her interior world into meltdown. Docter was partly inspired by his own daughter, Elie.
“She was about 11 at the time when we were working on it, and going through a definite change, as we all do.” All of a sudden, she became more insular, he says.
“It made him wonder – what is going on inside this little girl’s head?” says Docter’s co-director Ronnie del Carmen.
Docter realised that the emotional tumult youngsters must contend with was fertile ground to explore.
“I pitched a very basic scenario of a kid about to raise her hand in school and then gave voice to the inner struggle – the characters are going: ‘We know the answer!’ and then Fear is going: ‘What are you crazy? Did you see the way they judged that last kid when they got it wrong?! We’re not answering!’”
Kaling, like most of us, has been there and can identify with this conflict. “I’ve definitely felt that vulnerability,” she says.
It's this inner turmoil that gives Inside Out its drama, as Digust, Joy and their fellow emotions try to resolve the situation.
“Pete kept reminding us that each of the emotions are trying to do what’s best for Riley,” says Kaling, who was joined by a host of American comic stars to bring the characters to life.
Parks and Recreation star Amy Poehler is Joy, stand-up comedian Lewis Black is Anger, funnyman Bill Hader plays Fear and Phyllis Smith, Kaling's co-star on the The Office, voiced Sadness.
Since the film premiered in Cannes to ecstatic reviews, it has become one of the biggest hits of the summer. Grossing US$600 million (Dh220m) around the world in less than two weeks, it is the seventh Pixar movie to cross that box-office barrier – though it has some way to go to stand a chance of eclipsing the studio's $1 billion (Dh367bn) top-earner, Toy Story 3.
“Our hopes are always for our stories to do well, to find an audience,” says Del Carmen.
But perhaps Kaling puts it best: "Pixar is like Star Wars, right? Everybody is a fan and everyone has seen them all! When there's a new Pixar movie, you just go and see it."
• Inside Out opens in UAE cinemas today.