What I think this song is about is not so much an ex-girlfriend or lover, but a love that is absolute and unattainable. It's about wanting and needing her so badly as to be a constant source of heartache and pain, a devoted, passionate love with no boundaries which can never be a reality. Someone who is within reach, yet cannot be touched, so to speak. And it's as real in a spiritual sense as in a physical sense, encompassing both worlds, so it goes on for eternity, from lifetime to lifetime, in an ongoing cycle. There are other loves which can fulfill in part, but never fully satisfy, and the one love that can will never be obtained.