Until last month, when Pixar finally released a synopsis for the toon studio’s 15th feature, precious little was known about “Inside Out,” which takes place entirely inside the mind of an 11-year-old girl. But after director Pete Docter’s stunning presentation at the Annecy Intl. Animation Film Festival in southern France yesterday, one thing is clear: “Inside Out” will forever change the way people think about the way people think.

As Docter explained over the course of his one-hour, in-depth presentation to a packed house of animation professionals and fans, though this is by far the most high-concept project Pixar has ever undertaken, it started from a very personal and relatable place.

“It’s based on a strong emotional experience I had watching my daughter grow up,” says the “Up” director, who noticed that when his daughter Elie turned 12, much of her childhood joy disappeared, and she became more moody and withdrawn. “There is something that is lost when you grow up” — and the film became a way to explore that change on an emotional level.

The film centers on a young girl named Riley Anderson, “one of those kids who seems like she was born happy,” Docter says. “In truth, Riley is not our main character; she is our setting.” To demonstrate what he meant, Docter screened the first five minutes of the movie, a good segment of which was still in a pencil-drawn storyboard state. (The finished film will open June 19, 2015.) Sure enough, “Inside Out” takes place in Riley’s subconscious, where a crew of anthropomorphized emotions manage how the girl feels at any given moment from a control panel that looks something like the flight deck of the Starship Enterprise.

In the team’s research, they found many different scientific theories on how the mind works, including one from expert Robert Plutchik that defined eight primary human emotions, which Docter narrowed down to five: Fear (Bill Hader), Sadness (Phyllis Smith), Joy (Amy Poehler), Disgust (Mindy Kaling) and Anger (Lewis Black) — “like our version of Walt Disney’s Seven Dwarfs,” he jokes.

These distinct color-coded characters help Riley to process new experiences and to make memories, which are constantly being recorded within brightly colored orbs that look something like those translucent bath-bubble balls (filed away nightly and then erased in long-term storage by “Forgetters” with a vaguely Minions-like vibe). The inventive opening scene extends from the moment of Riley’ birth and the creation of her first memory to the introduction of its five main characters, ending with an encounter between Joy and Sadness where the former can’t seem to figure out Sadness’ role in the operation. Once the clip ended, Docter explained that Riley and her parents relocate from a quiet rural home to San Francisco at a particularly impressionable age, resulting in a new-school trauma that forces Joy and Sadness out of the control panel and into the far, unfamiliar reaches of her mind.

While Fear, Disgust and Anger awkwardly try to keep things under control — as illustrated in a second clip set around the family dinner table which Pixar unveiled at CinemaCon in March — Joy and Sadness put aside their differences and take audiences through a tour of Riley’s thinking process. This epic road trip entails crossing such areas as Imagination Land (“a giant amusement park full of everything Riley has ever daydreamed about”), a movie studio where nightmares are made, the Train of Thought (a free-ranging locomotive that can go zooming off in any direction) and Abstract Thought — the zone Docter had the most fun translating to the screen.

“I was pretty certain someone must have done an idea like this before,” Docter told Variety after the presentation. And yet, “we’re approaching it from a poetic viewpoint. It’s not even trying to be scientific at all.”

The system depicted in “Inside Out” is both intuitive and slightly retro, recalling such educational filmstrips as “Our Mister Sun,” whose “Gateways to the Mind” installment depicts a little man asleep at the controls. And yet, Docter and his team pushed to find a fresh metaphor that would be totally understandable to all audiences. “One of the big things in this film has been simplifying and making things ‘gettable,’” he says.

At the risk of overstatement, the film could eventually prove to be as revolutionary as Dante’s “Divine Comedy,” which so vividly described the Italian poet’s vision of heaven and hell that it has shaped the public’s image of both ever since. In the absence of a truly satisfying model for how the mind works, “Inside Out” gives people a new way to visualize their own thought process.

As if to prove that point, early reactions to internal test screenings reveal ways in which audiences are already analyzing their own behavior according to Docter’s new model.

“One family came and watched the movie,” the director recalls. “The son had always had trouble going off the diving board, and that day, he dove off, and he said, ‘I just felt like Fear was driving, and I needed to make him step aside.’”

Once the movie opens, it’s entirely possible others will embrace and adopt this visual way of understanding human behavior. The experience has certainly rewritten the way Docter analyzes his own emotions.

“There’s this whole system that’s basically designed to operate in your subconscious,” he says. “All of the impulses that control your decisions, actions, stuff like that is out of your control, which is not the way I like to think of myself at all.”

And though Docter is reluctant to say too much about the film’s particulars at this stage, he did concede another even more telling personal revelation he encountered along the way — one he expects will bond others to the story as well.

“I thought I was making a film about my daughter, but the truth is, I’m more making a film about myself in relation to my daughter and understanding that. The film is told from a parent’s point of view, and being a parent, I just sort of slipped into that, I guess. It’s definitely made me think again about the way I grew up, my adolescence, and even on a day-to-day basis what I’m doing and why.”