It is perceived by most (and seemingly proven time and time again) that most artists are in some way shape or form, insane. But do they have to be?
Beethoven heard music in his head so strongly that he had to write it down immediately, no matter where he was. Rumor has it his landlord ripped out the window sashes after his death and sold them at auction because they were covered in his handwritten music. Van Gogh, of course, cut off his own ear. Dali saw owls on peoples heads among other things. The Beatles were infamous weirdos, not to mention the extra levels of weird once Yoko came on the scene. Syd Barrett, Michael Jackson, the list goes on and on.