The BPS research digest reports:

"Imagine if wherever you looked, you saw a translucent mirror image of yourself, about one metre in front of you. It's wearing the same clothes as you and if you wave your right hand, it waves back in identical fashion (but with its left hand, just like a mirror image). That's what patient B.F. reported seeing three months after she was brain damaged during the still birth of her baby, when she experienced seizures and fell into a brief coma."

Explaining the phenomenon of autoscopy in the Journal of Clinical Psychiatry:

"Autoscopy is thought to be a rare phenomenon in which a person visualizes or experiences a veritable hallucinatory image of his double. It may be more common than has hitherto been thought [...] Autoscopy has been known since ancient times but came into prominence only in the nineteenth century, both in the romantic literature of the double and in neuropsychiatric research."

Human enquiry reports that:

"Goethe met himself on the road riding a horse. Shelley was approached by a hooded figure who pulled back the hood to reveal himself. Dostoievsky encountered himself, so too de Maupassant, and several others."