From the movie, The Ice Storm :
"To find yourself in the negative zone, as the Fantastic Four often do, means that all everyday assumptions are inverted. Even the invisible girl herself becomes visible and so she loses the last semblance of her power. Seems to me everyone exits partially on a negative zone level, some people more than others. In your life it's kind of like you dip in and out of it, a place where things don't quite work out as they should, but for some people there's something about the negative zone that tempts them and they end up going in...going in all the way."