Jon and Dan were in a mental institution. This place had an annual
contest, picking two of the best patients and giving them two
questions. If they answered correctly, they were deemed cured and free
to go.

Jon was called into the doctor's office first and asked if he
understood that he'd be free if he answered the questions correctly.
The doctor said, "Jon, what would happen if I poked out one of your
eyes?" Jon said, "I'd be half blind." "That's correct. What would
happen if I poked out both your eyes?" "I'd be completely blind." The
doctor stood up, shook his hand, and told him he was free.

On Jon's way out, as the doctor filled out the paperwork, Jon
mentioned the questions to Dan. He told him what questions would be
asked and the answers. Dan was called in. The doctor went through the
formalities and asked, "What would happen if I cut off one of your
ears?" Dan, remembering what Jon had said, said, "I'd be half blind."
The doctor looked a litle puzzled, but went on. "What would happen if
I cut off both your ears?" "I'd be completely blind." "Dan, how can
you explain that you'd be blind?" asked the doctor. "Well," replied
Dan, "my hat would fall over my eyes."