During a visit to the mental asylum, a visitor asked the Director what the criterion was which defined whether or not a patient should be institutionalized.
"Well," said the Director, "we fill up a bathtub, and then we offer a teaspoon, a teacup and a bucket to the patient and ask him or her to empty the bathtub."
"Oh, I understand," said the visitor. "A normal person would use the bucket because it's bigger than the spoon or the teacup."
"No." said the Director, "A normal person would pull the plug."