There was recently some posts about dissociation and the lack of information of the spectrum rather than DID, the most extreme end of the pole.

There's lots of info about it -- look up "depersonalization", "derealization", Schizoid, and other terms.

I've found reading about schizoid phenamena to be the most helpful.

And like Larry said, we all dissociate to some degree or another -- it's probably as necessary as sleeping to maintain our health.