First year medical students were receiving their first anatomy class with a cadaver. They all gathered around the table with the body covered with a white sheet. The professor started the class by telling them; “In medicine, it is necessary to have two important qualities: the first is that you can not be disgusted by anything involving the human body”.
For an example, the professor pulled back the 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,” The students hesitated for several minutes, but eventually took turns sticking a finger in the anus of the corpse and sucking on it.
When everyone finished, the professor looked at them and told them; “The second most important quality is observation. I stuck in my middle finger and sucked on my index finger. Now learn to pay attention.”