And... here's a list I had of "Awesomely Weird Mental Disorders", as I called it. I did a lot of research for this. If you find any more, let me know, I'll add it to the list!
Capgras's Syndrome - individual does not recognize faces. Thus believes close acquaintances or family members to be identical imposters.
Cotard's Syndrome - individual believes he or she is dead.
Synesthesia - gets senses mixed up. The color blue tastes like blueberries, the sky sounds like a harp...
Foreign Accent Syndrome- due to a blow to the head, the individual begins speaking in a completely different accent.
Boanthropy - individual believes himself/herself to be a cow.
Alien Hand Syndrome - The individual's hand takes on a mind of its own.
Lima Syndrome - opposite of Stockholm syndrome, where the kidnappers become extremely sympathetic to their hostages.
Reduplicative Paramnesia - individual believes that a place or location (often their own home) has been duplicated or relocated to another location.
Zero Stroke - from Germany after WW2, this is caused by an insane inflation rate causing immense numbers of zeros, and requiring advanced math just to calculate grocery costs. The individual eventually sees zeros all the time, even when sleeping, and will refer to themselves as 40 billion years old, or some such.
Wild Pig Syndrome - individual goes on a shopping or stealing spree for several days, not caring for consequences, and comes back not remembering a thing.
Jumping Frenchmen of Maine - individual will obey any command given in such a way as to startle them. ("Jump out a window!" for instance.)
Environmental Agnosia - is the inability to locate a specific room or building that one is familiar with, as well as the inability to provide directions for how to arrive at a particular location.
https://en.wikipedia.org/wiki/AgnosiaTime Agnosia - is the loss of comprehension of the succession and duration of events.
https://en.wikipedia.org/wiki/AgnosiaFregoli Syndrome - individual believes that everyone is the same person.
Mirrored-Self Misidentification - individual does not recognize themselves when they look in a mirror. Or they think it's a doppelganger, long lost twin, etc.
Visual Agnosia - Individual has trouble knowing the difference between objects and people - putting bread in brother's hair cuz they think he's a toaster.
Somatoparaphrenia - doesn't recognize a body part (usually a limb) as their own, think's it's been grafted onto them.
Anosognosia - a paralyzed individual refuses to believe they're paralyzed.
Prosopagnosia - individual doesn't recognize anyone, is convinced that all are total strangers. This is NOT memory loss, simply an inability to match familiar faces with memory of individual.
Historical rulers who were insane:
King George the third - straitjacket
Charles the Sixth - thought he was made of glass and could break.
Justin II of Byzantine heard voices, had organ music played to drown them out.
The Zhengde Emperor of China - played make-believe