Appropriately enough, Self in this post-modern age is a highly commercialized, brand-focused magazine 'full of sound and fury, signifying nothing'. Ghosts lack self, or do they possess, instead, a heightened sense of self, one that remains focused on a single aspect of the self as opposed to our usual contradictory maelstrom of aspects? Is this still more Supercalifragilisticexpialidocious stuff? Here's the Straight Dope on that, but then again, as an example of the divided self, here's another kind of Poppins, not Mary