Medical Students A group of first year medicals students are attending their first class. An eccentric looking lecturer walk in and says: ""An important thing in medicine, is not to be fazed by what seems disgusting to the general public. Allow me to demonstrate"" The lecturer brings a cadaver into the lecture theatre and shoves a finger up the cadaver's anus and promptly licks his finger. The lecturer tells the reluctant students to do the same. So, one by one they begrudgingly shove their fingers in the anus and lick them afterwards. After everyone has finished the lecturer says: ""However, the most important thing in medicine is observation. I shoved in my ring finger and licked my index finger."" (from QI)