I believe the song deals with living and dying (a common theme in their music I've noticed) as well as commenting (and possibly lamenting) on how humans are just one part of a greater cycle and all we can really do is just live our life the best we can ("respecting the animals" as they are part of the same cycle) and do what we love (or be with those we love) until we can't anymore: "Don't turn away from what you love
Soon you'll be finding it's much too tough" because no matter what we do in our lives, in the end: "May we all turn into leaves that crack and break apart." I don't think they necessarily look at this as a depressing thing, just a truth that should be realized to keep on the right path.
I believe the song deals with living and dying (a common theme in their music I've noticed) as well as commenting (and possibly lamenting) on how humans are just one part of a greater cycle and all we can really do is just live our life the best we can ("respecting the animals" as they are part of the same cycle) and do what we love (or be with those we love) until we can't anymore: "Don't turn away from what you love Soon you'll be finding it's much too tough" because no matter what we do in our lives, in the end: "May we all turn into leaves that crack and break apart." I don't think they necessarily look at this as a depressing thing, just a truth that should be realized to keep on the right path.