The film opens with Carl as a child, thinking as a child. He meets Ellie in an abandoned, ramshackle, and empty house, which they imagine is an airship. We then skip forward in time to the pair as young newlyweds. Crucially, the first thing they do as a couple is buy the old abandoned house and fix it up, not so much putting aside childish things as literally transforming them into that most adult of things, a household. (And presumably a mortgage? I’m a little unclear on their finances.) And then they start thinking of children. It’s all part of the process, after all… first comes love, then comes marriage, then comes –
Then comes infertility, throwing a wrench into the gears. Ellie takes it harder than Carl, leaving him with the task of figuring out how to fix the situation. Most people would probably say something like “It’s okay, honey. So we can’t have kids of our own… we can always adopt.” Carl attacks the problem from a different angle. “It’s okay, honey. So we can’t have kids of our own… we can always regress.” The room that was to be their nursery becomes instead a shrine to the globe-trotting adventure they had dreamed of as children. That this should be seen as a regression is made explicitly clear by the central role of Ellie’s childish drawing of Paradise falls, and by the fact that they keep their trip fund in a piggy bank instead of a savings account. Upon Ellie’s death, Carl regresses further, pranking his enemies and refusing to deal with his problems. (The moment when he hits the construction worker and then runs into his house to hide rather than helping the man up and apologizing is telling.) Traveling to Paradise Falls is perhaps the ultimate regression, acting out a childish fantasy (running off to live in South America) in a childish fashion (house lifted by balloons). And isn’t it interesting that the house regresses right along with him? Over the course of the trip, it becomes progressively more damaged, until, at the end, it is broken down, empty, and abandoned just like it was at the beginning. What ends up sitting atop Paradise Falls is not the home Carl and Ellie built together, but the clubhouse they played in as children. And along with their clubhouse, Carl encounters another fixture of his childhood dreams: the explorer Charles Muntz.