I don't think of dissociating as good or bad. I think that it is often used as a coping skill. I'm not a professional, so I'm not sure what to tell you beyond that, but I think that often, we develop certain "coping skills" in order to survive bad situations. It's just eventually we are no longer in those situations, but we still tend to use those skills. Thru therapy some people learn how to work thru those old patterns. I have a tendency to retreat into my own world alot when things are stressful--or if they seem stressful.