Attention to Details

I heard this some time ago:

In pre med school the Professor was standing upon a corpse with all the new "Doctors-to-be". He says: "There are two very important lessons I'll give you today... Lesson One: you should not be afraid or disgusted of the body, or the dead body.... “
At that time he proceeded by inserting his finger into the corpse ass hole and extracted some stuff...
Then he proceeded: "You will need to examine and operate on the body too see what went wrong… “
Then he proceeded by licking his finger, showing he is not afraid or disgusted. He told the students to do the same.
Some student left, but some inserted their finger then licked it, proudly showing how strong and ready for being doctors they are.
After all students either left or put and licked their finger he said “Lesson Two: I inserted this finger, and licked THAT finger… PAY ATTENTION!