I disassociate all the time, have since I was about 10, but the thought of nonexisting terrifies me. I saw a tv show a few years ago about a woman who died and no one could be found who ever knew her. She had no friends, she worked at a temp agency and no one could remember ever working with her, and they placed an ad in the paper trying to find anyone who knew her and they couldn't. The show gave me nightmares for some time afterward.