These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
And You Thought It Would Fail: Michael Eisner, CEO of Disney, stated publicly that he thought Pixar would be taken down a peg by this film's probable failure. Instead, the film became a megasmash hit that outgrossed The Lion King which happened at the worst possible time for him in not only undermining his reputation for his skill in the entertainment business, but it also came out near the end of Disney's contract with Pixar, putting the studio in a position of unassailable strength after a string of five consecutive blockbuster hits and owned by Steve Jobs, who loathed Eisner. At this threat of this movie powerhouse going to their competitors, the Board of Directors got rid of Eisner in part to placate Jobs.
"First you were like "Whoa!," and we were like "WHOA!" , then you were like "Whoa...."
The Internet delights in making the film sound like a horror film: "An optimistic young family is brutally attacked by a serial killer. The mother is murdered and eaten, along with all her children, the father is traumatized, and their only remaining son is physically disabled. Years later, that son is kidnapped and his father must track him down with the help of a mentally disabled woman."
Almost even more memetic, pointing out that Clownfish are sequential hermaphrodites and reproduce with their family members in time of emergency.
After the 3D re-release, a new meme was sprouted: Marlin appearing randomly screaming "HAVE YOU SEEN MY SON??" in various pictures and other movies.
The DVD commentary said that the take they used was her second one - by the end of recording the first one, she was crying so much because she thought she had ruined the line, and she had to take a break. By the second try, she was still distraught over the first take. An example of accidental method acting.
What Do You Mean, It's for Kids?: Slaughter in the first five minutes, harsh reminders about the true nature of an ocean ecology (i.e. brutal and unforgiving), a missing child kidnapped and placed in a small confined space with creatures driven insane by their confinement and isolation, a neurotic father whose traumatic death of his partner scarred him for life, and an amnesiac with modified forms of both anterograde and retrograde amnesia who holds no memory of her identity? Yep. Sounds like a kid's movie. This is one of those rare times when it's not the individual content of the scenes that act as a Parental Bonus but the context and serious subject matter that underlie it when translated to a human perspective.
The Woobie: Nemo, Marlin and Dory. Especially Nemo in the first tank scene.