We don’t know why Carl had millions of balloons lying around his house, but we’re sure glad that he did. Without those helium-filled suckers, Carl never would have taken off, and neither would Up’s adventuresome story.

The balloons in Up symbolize the wonderment and spirit of childhood. When we first meet Carl, he’s a kid toting a balloon with “The Spirit of Adventure” scrawled on it. Later, when a pint-sized Ellie wants to get in touch with Carl, she sails a balloon through his open bedroom window. At the end of the montage celebrating Carl and Ellie’s marriage, Carl scoots a similar balloon into Ellie’s hospital room. It’s a reminder of their fun-filled past, and encouragement to keep her spirits high.

If the balloons in Up represent the awe and amazement of childhood, then they also symbolize Ellie’s spirit—specifically the massive bundle of balloons that helps Carl carry their home through the jungle. Although we don’t see a whole lot of Ellie, it’s clear from the glimpse that we do get that Ellie had a buoyant personality. That’s why she was such a solid match for our main man Carl. He was grounded and stable; she was bright and carefree. When Carl looks to the sky to talk to Ellie, he looks not just to the heavens, but also toward the buhzillion balloons hovering over him like so many helium-filled guardian angels.