Learn to pay attention

First-year students at Texas A&M's Vet School were receiving
their first anatomy class, with a real dead cow. They all gathered
around the surgery table with the body covered with a white sheet. The
professor started the class by telling them, "In Vet Medicine it is
necessary to have two important qualities as a doctor: The first is that
you not be disgusted by anything involving the animal body. For an
example, the Professor pulled back the sheet, stuck his finger in the
butt of the dead cow, 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 anal opening of the dead cow 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."