If you've seen the PHENOMENAL 2015 Pixar movie Inside Out, you know all about how the memory orbs in Riley's brain work.
Well, Redditor HellotoHorse noticed a detail that you might have missed, even if you've seen the movie a bunch of times. While Joy and Sadness are going through Riley's long-term memories...
...there's a shot that includes memories that happened in Pixar's other emotionally scarring movie, Up! Specifically, there are two sad memory orbs featuring Carl and Ellie's wedding and their house.
So in the context of the movie, if Riley has seen all these moments from Carl and Ellie's life, this could really only mean one thing: Up is just a movie in the unified Pixar universe, and it never really happened!
Or maybe the team making the movie just needed some already-rendered scenes to put in the memory orbs, so of course they used old Pixar movies, but WHERE'S THE FUN IN THAT, HUH?
Anyway, this either makes me very sad that Carl and Ellie never existed or very happy that I never have to feel like someone is stabbing me in the heart while I watch the beginning of Up ever again.