I've been listening to Sam Harris' new book, Waking Up , which is an attempt to provide a scientific justification for the "spiritual" experiences that can achieved through meditation and certain Eastern religious teachings. The fundamental notion seems to be that our feeling of being a contained "self" is an illusion, and that by trying to pay attention to the present moment, this truth can be perceived to positive effect.
It's not worth trying to lay out the case - the book is really quite short and worth reading (and I'm no expert despite my parents in law being zen masters), but I bring it up because this morning I listened to the most recent episode of Invisibilia, a new NPR show about invisible forces. They describe a condition called "Mirror Touch Synesthesia," in which people's neural wiring for empathy is over-active, causing people to feel the sensations (physical and emotional) of other people. This can be so extreme that people loose the sense of their own individuality, somehow feeling blended in with other people.
My first thought was that this condition might make the realization Harris speaks of easier, since it's almost natural for these patients to lose their sense of self (incidentally, there's a brain region involved in the sense of self that is under developed in mirror sysesthetes), but then I wondered, would it actually be more difficult since you don't only have to abandon your own sense of self, but your sense of other selves as well?