First-year students at Med School were receiving their first anatomy class with a real dead human body. They all gathered around the surgery table with the body covered with a white sheet.
The professor began the lecture by telling them: "In medicine, it is necessary to possess two important qualities as a doctor. The first is that you not be disgusted by anything involving the human body". To illustrate, he pulled back a sheet, stuck his finger in the anus of the corpse, withdrew it, and stuck it in his mouth. "Go ahead and do the same thing," he told his students.
The students freaked out, hesitated for several minutes, but eventually took turns sticking a finger in the butt of the dead body
and sucking on it.
When everyone finished, the professor looked at them and said, "The second most important quality is observation. I stuck in my middle finger and sucked on my index finger. Now learn to pay attention."