Jon and Amanpreet were in an institution.  This place had an annual contest where they picked two of the best patients and asked them two questions.  If they got them correct, 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 if I poked out both eyes?"

"I'd be completely blind." The doctor stood up, shook Jon's hand, and told him he was free.

On Jon's way out, as the doctor filled out the paperwork, Jon mentioned the exam to Amanpreet.  He told him what questions were going to be asked and gave him the answers.

So Amanpreet came in.  The doctor went through the formalities and asked, "What would happen if I cut off one ear?"

Amanpreet, remembering what Jon had said, answered, "I'd be half blind."

The doctor looked a little puzzled, but went on.  "What if I cut off the other ear?"

"I'd be completely blind," Amanpreet answered.

"Amanpreet, can you explain how you'd be *blind*?"

"My hat would fall down over my eyes."