Five years after its release, “Cars 2” still instills dread in Pixar lovers. Never mind that the studio’s other weakest films (“The Good Dinosaur” and “Brave”) are both original works, and that the “Toy Story” followups have been lauded as some of the best sequels ever. What most people think of when they hear about returning to a beloved Pixar world is Mater the Tow Truck zipping through Japan and making pee-pee jokes.

It’s why the idea of a “Finding Nemo” sequel made me uneasy, especially once it was announced that the film would focus on Dory, the cheerful, memory-impaired sidekick. Thirteen years ago, Dory — voiced with lovable daffiness by Ellen DeGeneres — was a burst of wit, energy and charm, paired with the world-weary and neurotic Marlin (Albert Brooks). But Dory was largely a one-joke character; even if that joke was often funny, is that enough to rest an entire film on? Wouldn’t the very things that made Dory so endearing be annoying when magnified?

Well, rest easy: “Finding Dory” doesn’t turn the world’s favorite Blue Tang into Mater. The sequel isn’t quite peak Pixar, but it’s a clever, funny and enjoyable adventure that shows us a new side of the character. And yes, you will cry.

In its opening moments, the film shows how Dory, who suffers from short-term memory loss, was separated from her parents (Diane Keaton and Eugene Levy) as a child and eventually met up with Marlin on his search for his son. One year later, the three are living happily in their anemone, when Dory suddenly recalls a memory of her parents. She compels Marlin and Nemo to help her travel to California to find them, and the trio eventually makes its way to a marine rescue park, where they must navigate various exhibits and rely on the help of new friends.

The plot is similar to “Finding Nemo’s,” but directors Andrew Stanton and Angus MacLane don’t pepper the film with too many callbacks. A cameo of some returning friends gets out of the way quickly, and the film separates Dory and Marlin early so they’re off on their own adventures, not simply rehashing the dynamic of the first film. And by centering the majority of the film inside the aquarium/marine park, the film places the characters in a setting that provides new challenges and dangers. It also introduces some memorable new characters, including an escape artist octopus (technically a septopus) named Hank (Ed O’ Neill), a nearsighted whale shark (Kaitlin Olson) and her beluga friend (Ty Burrell), and — most memorably — two lazy sea lions voiced by Idris Elba and Dominic West. Sure, I miss the first film’s Tank Gang and seagulls, but the sea lions’ bark cracked me up every time.

The film is Dory’s story, and its biggest triumph is the way it adds depth to a character who was previously comic relief. From its first scenes, the story repaints Dory’s memory loss not as a joke but a disability, and suggests that her cheerfulness is a protective device she wields to keep people from abandoning her. If “Finding Nemo” was a story of parental fear, “Finding Dory” is about living with impairment. The film showcases Dory’s disability not as a cute quirk but as an often terrifying and heartbreaking struggle. “What if I forget you?” Dory asks her parents as a kid. “What if you forget me?” In several scenes, the bright and colorful coral reef of the first film is switched out for shots of Dory alone in the middle of the inky ocean, plagued by the terrible fear that she doesn’t know where to go or why. It’s sometimes very upsetting, and gives us more insight and empathy toward the character. It’s the opposite of “Cars 2,” which cranked up all of Mater’s annoyances but robbed him of any endearing aspects.

In most films, Dory would overcome her disability all on her own and prove everyone else wrong. But Pixar has always been unafraid to deal honestly with life’s harsh realities. Dory doesn’t learn to overcome her short-term memory loss, but instead to rely on others, whether that’s strangers or close friends. Most strikingly, the film examines the patience and unconditional love of parents who go to great lengths to help their children succeed in spite of their limitations, an inversion of “Finding Nemo,” where Marlin tried desperately to shield his son (born with a small fin) from the dangerous world. In flashbacks, we see Dory’s parents teaching their daughter how to find her way home and what do do if she ever gets lost (her “just keep swimming” song gains resonance). The culminates in a powerful display of parental love and patience, where the image of a thousand seashells will have many reaching for a tissue.

Of course, “Finding Nemo” wasn’t just emotionally affecting; it’s still one of the flat-out funniest films in the Pixar canon. DeGeneres and Brooks made a great comic duo, with his frustration a perfect foil for her exuberance. The actress has a similar rapport with O’Neill, but the Hank has a crustiness to him that’s a lot of fun, and there are several great gags regarding his camouflage abilities. The aforementioned sea lions provoke some big laughs, and DeGeneres still knows how to sell the role of a lovable dimwit very well. Marlin and Nemo, however, are shortchanged here, with a subplot that doesn’t give them much to do; honestly, the movie could have worked with a cameo from the two and then let the movie shift to Dory’s adventure.

The film’s clever chase sequences move with energy, and Stanton and MacLane find several ways to play with the world outside the water — including a chase involving an octopus driving a truck. The humor is a bit more frantic and dependent on slapstick than “Finding Nemo,” but it’s fast and fun. The film introduces memorable new characters without bogging the film down, and there are several solid gags peppered throughout; a recurring joke about a celebrity gets funnier each time. And, of course, in the rare minutes the film slows down, the animation is gorgeous.

And yet, “Finding Dory” still comes off a bit slight. As fun as it is in the moment, very little sticks to the ribs. Much of that has to do with the fact that it can’t escape the shadow of “Finding Nemo,” a movie that sits near the top of the Pixar pantheon. Everything about that film still is more focused and energized than “Finding Dory,” less a problem with the new film and more the result of Pixar’s team working at the top of its game. An ocean-wide adventure is more thrilling than a trip to the aquarium, “Nemo’s” parental issues felt a bit more subtly and organically woven into the story, and each joke hit a little harder. “Finding Nemo” is a great movie; “Finding Dory” is merely very good.

It’s also hard to escape the awareness that “Finding Dory” is yet another sequel from a studio best known for the way it’s broken the mold in animation. Last year’s “Inside Out” was a reminder that the studio is still capable of delivering brilliant, emotional and groundbreaking work. And “The Good Dinosaur” may have been a stumble, but it was an ambitious one that pushed the boundaries of photorealistic animation. “Finding Dory” works much better than “The Good Dinosaur” and is much more enjoyable, and it works much better than “Cars 2” or “Monsters University.” But you still can’t shake the feeling that Pixar is going back to the well. It’s funny and moving, and it’s great to see all the characters again. But I feel we’ll forever be chasing that feeling of newness that we had with “Inside Out.”

Is that unfair to “Finding Dory”? Perhaps. The film stands on its own, and I have no doubt that many who loved the first film are going to embrace this one. And they should. It’s a lot of fun, it’s emotional and it expands the first film’s story in some surprising ways. But unlike Dory, I can’t forget things easily. And Pixar has raised the bar so high that even a very good film can’t quite clear it. But hey, mid-tier Pixar is still better than the top-tier of most studios. Dory’s return might feel a bit familiar, but it’s still good to see her.

Note: Per tradition, “Finding Dory” is preceded by the latest Pixar short, “Piper.” I won’t say much about it except that the animation is another step forward for the company and audiences should be sufficiently warned about cuteness overload.