As I listened to the song, I found that the meaning was to enjoy life. It's all about finding and experiencing the joys of life. Its' a response to how people taking living and the things they have for granted. We don't see what is in front of us everyday, like the ocean, the sun the sky and everything else that involves nature.
The symbolism of the song is that if we were dying we would see all the goodness of life which refers back to the phrase that "You don't know what you have until you've lost it." We find joy in superifical and materialistic things, power, and status, when the real things keeping us alive are the inanimate objects that surround us everyday. For instance oxgen gives us air and water. We also forget the living things that we find worthless such as ecosystems, forests etc.
The only way we could find the real worthwhile things is if we knew that our days on earth were coming to an end.
