A guy thought he was dead, but in reality he was very much alive.
His hallucination became a real problem for his family and they finally took him to see a psychiatrist.
After spending many laborious sessions trying to convince the guy he was still alive, the psychiatrist tried one last approach. He opened his medical book and proceeded to show the man that dead men don't bleed.
After a mind-numbing study, the man seemed convince that dead men don't bleed, and the psychiatrist asked: "Do you now agree that dead men don't bleed?" "Yes I do" the man replied. "Very well, then," the psychiatrist said. He took out a pin and pricked the man's finger. Out came a drop of blood. The doctor asked. "What does that tell you?" "Oh my goodness!" The patient exclaimed as he stared doubtfully at his finger…. "Dead men do bleed!!"