A state of being in which you love being alive and attempt to experience the widest range of emotions and situations - yet simultaneously and continuously, couldn't care if the world ended right now.
Contrary to normal schizophrenia, sufferers of this disorder are aware of their predicament. In fact, many patients are known to be the first to diagnose themselves as suffering from the same. Interestingly, the moment of identification has been referrred to by several self-diagnosing patients as and "epiphany". In the words of Sarita Nair-Singh, one of the earliest known cases:
"I first realised what I was going through on a day in Spring. It was a lovely day - warm enough to be comfortable, and breezy enough to keep you cool, with passing clouds providing occasional shade. I was lying on the grass in a public park, and while taking a break from reading my book, I noticed a small daisy plant growing nearby. It was rather unremarkable, but the more I looked at it, the more I marvelled at its very existence - at the way they followed the seasons so carefully, at the way they had formed a symbiosis with everything around them in order to exist, and at the beauty they provided to others who it did not really need in order to survive. And these were supposedly non-thinking creatures! And I thought of the whole world of ours, and the way everything fits, and it was .... uplifting.
But then somebody happened to walk across, stepping on the flower. And when I thought some more, especially of our world in the larger cosmos, I realised nobody would really miss us much if the whole Earth was gone. Worse, nobody would probably even know we were ever here. Because, at the end of it all, we're just cosmic sludge. Somewhat sentient sludge, I grant you, but just....effluvium nonetheless. And I realised I wouldn't miss us either. Because a world where people step on flowers, and tear them up so that they can pretty up their houses, doesn't really mean much.
I spent the rest of the afternoon fantasising how people would react if a bomb exploded nearby - or an alien warship dropped from the skies and started zapping us all. It was....enlightening."
Existential schizophreniacs are known to actively explore the depth of the breach between the two differing states, which unfortunately often leads to further hardening of the inherent disparities.
Dementia is an almost certain eventuality, unless the patient decides in favour of one of the two options. It is therefore recommended that such people are closely watched, especially if they tend to make repeated (wistful) references to weapons of a particularly destructive nature.