For two decades, Pixar has been making some of the warmest and most wonderful movies on the planet, but it feels like it's been a while since they've done something as simple and brilliant as "Inside Out." It's perhaps the best concept they've had since "Toy Story."

For two decades, Pixar has been making some of the warmest and most wonderful movies on the planet, but it feels like it's been a while since they've done something as simple and brilliant as "Inside Out." It's perhaps the best concept they've had since "Toy Story."

Set in the mind of an 11-year-old girl named Riley, it personifies five key emotions that help run the show of maintaining memories that formulate Riley's personality.

It's actually a pretty heady concept, but it's pulled off in a way that's simultaneously kid-friendly and deep enough to spark discussion among grown-ups. Added bonus: It's cheaper than therapy.

Joy (voiced by Amy Poehler) takes a leadership role in Riley's head, but her other emotions - Fear (Bill Hader), Anger (Lewis Black), Sadness (Phyllis Smith) and Disgust (Mindy Kaling) serve key functions in formulating Riley's persona.

Director Pete Docter has been involved with Pixar since "Toy Story," having directed "Up" and "Monsters, Inc." among many other credits, but the imagination and execution of "Inside Out" put it right alongside Pixar's best.

For starters, that voice cast is such a perfect fit. Poehler's natural enthusiasm is a perfect Joy, and she's got an unlikely companion in Sadness, performed by Phyllis Smith of "The Office." Even the obvious casting of Lewis Black as Anger works even better than it does on paper.

As Riley moves from her Minnesota home to San Francisco, the turmoil provides a grand adventure in her head and a perfect setup for some lovely representations of a young child's feelings and imagination. The set pieces make for some gorgeous animation, while "Inside Out" also feels like it's more focused on story than selling toys - which can be a rarity among animated films.

The dissection of what's going on beneath the surface is actually quite thoughtful as well. I know some adults who could stand to learn the lesson presented here; essentially, your feelings are there for a reason.

"Inside Out" has some flaws - a little repetitive in places and a supporting character who doesn't quite take off - but it's a brilliant and original idea that's well-executed. And there hasn't been enough of that this summer.