I've often wondered the same thing. Here's my take today - subject to change as I learn more about my own personal motivations - that we hang onto the hope for change. We know addicts who can change their entire lives. We know what reality looks like without a substance to muck it up and blur everything.
I also think the death of the dream is a hard one to let go of. But everyday that goes by I let go a little bit more. Because I realize there was one person having this dream and it was ME. Hello! Why am I forcing my dream on someone who doesn't want it? Why not go find someone who does?
You aren't the only one who feels this way. Its hard to let go, even without the ties that bind people together. All I need to do is sign a piece of paper and take it to the courthouse. He can't fight me on it - contested is just a word in the file.
I haven't done it yet. I don't know why yet. But I know I will know when it is time to let go, and that it will most likely happen sooner rather than later. Because now I know I will be ok without this. And life will go on and be whatever I choose to make of it.