Jennifer read this over the weekend and suggested I read it too. With two young kids, a Pixar movie is usually on the television at some point during the week.

The theory is that all of Pixar's movies exist within the same universe.

We also learn that this witch inexplicably disappears every time she passes through doors, leading us to believe that she may not even exist. Don’t get ahead of me, but we’ll come back to Brave. Let’s just say, for now, the witch is someone we know from a different movie in the timeline.

— The Pixar Theory by Jon Negroni

Read on for the full explanation. Great fun for the adults being able to piece the movies together.