I actually think it goes two ways:
1) he's talking to the drugs/addiction falling back into it's vices
2) he's talking to an ex that left because of the addiction
(Thanks for posting the lyrics, I wasn't sure if we could do that...so I took the safe route.)
But, I really wonder what everyone else thinks?
I was going to try to hide this, but I couldn't figure out how to do that.
