It's sad, but it makes sense.

Fan theories are always popular from this crazy Grease theory that's been around forever, to Sarah Jessica Parker dropping her own bombshell of a theory about Sex and the City. And Disney movies are no exception to this. For anyone who hasn't seen Up, it's about an elderly grumpy man named Carl who finally sets off to paradise falls after all promising his late wife that he would. The adventure with his new friend Russell is full of fun and friendship. However, according to Digital Spy, one popular theory among fans is that Carl is actually dead the whole time. (Why is it that fan theories are always 'he was dead the whole time'?) So while this seems pretty sad, and dark, it actually makes sense and gives new meaning to the film. The idea is that the night before Carl is due to be moved to a nursing home, he passes away in his sleep. His balloon filled journey up into the sky is actually his passage to heaven. It is also believed that Russell is actually a guardian angel helping him on his way. Russell apparently took the form of a little boy to make up for Carl and his wife Ellie's inability to have children of their own. So this all sounds a bit heavy and the alternative is much much nicer, however, this one kind of makes sense. Even if this was not the writers intention, it is a nice metaphor for an elderly person letting go and leaving this world for a better place. It's all open for interpretation, but we've heard crazier ones than this.