YES. You said it perfectly. I have been a IV heroin addict for years now and have been to rehab after rehab, but I can't find it in me to quit despite with others tell me. It is out of control before you can even realize you have a problem. In my personal experience, it is something that is always there for me. I know for a fact that it will make me feel better (while I am high). Eventually, all heroin addicts get to the point where we no longer really get high from it anymore, we just feel normal and not dope sick. After years of shooting up around 4--5 times a day, everyday, I simply do not know how to live without it. I don't know how to deal with life without using. Or how to deal with my emotions, the good and bad, without it. Which I know, is ridiculously pathetic. The first thing that it changes in the brain is your reasoning and decision making. I would not wish a heroin addiction on anyone. Well any addiction for that matter. It is the hardest thing I have dealt with in my life by far.