so punk rock,
after you click on Dissociative Disorders forum to get here, at the top of the page are listed several "sticky's" or detailed information about D.I.D., especially the first "sticky" Understanding the Dissociative Disorders.

there are many different "levels" if you will, from very mild dissociation such as everybody experiences when, say, driving and you forget momentarily and then realize you missed your turn! up to and including the mind splitting off into different and distinct personalities. in between are fugue states, amnesia, depersonalization, derealization, and others. just FYI