I'd say it's extremely unlikely that you haven't thought about the possibility that the talking fish of Finding Nemo exist in the same universe as the talking rats of Ratatouille or the talking insects of A Bug's Life. In fact, a lot of Pixar's filmography could well be interlinked. Well, Cars kinda scuppers all of that... But nonetheless, I doubt you've thought about in as much detail or as cripplingly hilarious a fashion as Jon Negroni.
According to Negroni's "Pixar Theory", which is making the rounds online, A Bug's Life is post-apocalyptic, Monsters, Inc. is set in the distant future and the witch from Brave is actually a time-travelling Boo looking for Sulley through time and scattering Easter eggs to help him find her. Oh, and "Wall-E is basically Robot Jesus". The theory is so massively extensive, at least some of it has to be true... right?
Check out the hilariously ridiculous and ridiculously hilarious theory in all its extensive glory here.