It’s a typical day at the asylum, and the duty psychiatrist is doing his rounds of the wards with a couple of medical students.
They look in on one patient and the pychiatrist says to his students, “Sometimes this fellow thinks he’s a temptress in a Bizet opera, but today, as you can see from his goose stepping, he thinks he is the World War II head of the Luftwaffe. What condition do you think he’s suffering from?”
The first student replies, “Is he a paranoid schizophrenic with a multiple personality disorder?”
The second student says, “No, surely he just doesn’t know whether he’s Carmen or Goerring.”
Image used under a Collective Commons License from: https://commons.wikimedia.org/wiki/File:The_Joint_Counties%27_Lunatic_Asylum,_Erected_at_Abergavenny.jpeg