Hold on to your hats guys, because this one could be a bit of an emotional roller coaster. Tumblr user Ranting Randall may very well have explained exactly why Monsters, Inc. was followed up with a prequel instead a sequel - because James P. 'Sulley' Sullivan was killed.
I know, I know it's quite upsetting, but unfortunately there's a nice piece of evidence to back this one up. So strap in, maybe get those tissues ready and check out this monstrous Monsters, Inc. theory:
In Monsters, Inc. the city of Monstropolis collects the screams of children to use as power
But despite scaring children for a living, the monsters of Monstropolis are just as scared of children, as the children are of monsters.
But why were monsters so scared of humans? Well, Randall had a pretty good theory:
Of course, Sulley was pretty dismissive of Randall's warning
But in the Toy Story Toons: Partysaurus Rex short film, what do we see on the toilet in Bonnie's bathroom?
ARGH, Mike had it right all along!
But there is one other possible explanation for Bonnie's toilet seat cover - it could be the result of a Code 2319: