First-year students at Medical 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 started the class by telling them
"In medicine, it is necessary to have two important qualities as a doctor.
The first is that you should not be disgusted by anything involving the human
body".
As an example, the Professor pulled back the sheet, stuck his finger in the
backside of the corpse, withdrew it and stuck his finger 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 into the dead body and sucking on it.
When everyone had 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!".