Anecdotal Evidence brings my attention back to "Robert Walser, a strange, unclassifiable, utterly lovable Swiss writer":
Walser, born in 1878, entered a mental hospital in 1933, when he stopped writing, and remained there until he died in 1956. This Christmas will mark the 50th anniversary of his death. Walser was an inveterate walker – many of his stories begin as walks – and his body was found that day in the snow. He had suffered a heart attack. A visitor, who had asked why he no longer wrote, quoted Walser as saying, "I am not here to write but to be mad."