Aerials by System of a Down
It's a metaphor for life.
"Life is a waterfall; we're one in the river and one again after the fall"
It's really not a hard song to decipher. Just look up the lyrics, and they're pretty straight forward. Really though, the basic meaning of it (by my interpretation) is the only time we're actually alone is in death. Once reborn, either in spirit or in body, we're all together again.
It's just another way of saying "we're all people, and we're all in this together."
