Don't get mad at a dog -- nor a jerk

Learned from CareerTrack tape on "21 ways to defuse anger and calm people down."

The speaker Michael Staver cited a conversation he had when he was a grad student with a visiting Dr. in Psychology. It happened in a big auditorium.
The Dr. asked why he was angry. He said his boss was a jerk.
The Dr. asked how angry he was in the scale of 1 to 10, 10 being the most. He said 8.5.
The Dr. asked him what was the definition of jerk. He said "stupid, foolish people." The dictionary confirmed the definition.
Then, The Dr. said "have you been mad at a dog walking on a leash?"
He said "No. why should I?"
The Dr. said "Have you went up to the dog and yell "you stupid dog, why are you walking on a leash?'
He said "No. Why should I?"
The doctor asked "why shouldn't you?"
He said, "It is a dog. A dog does what a dog supposed to do."
The doctor then said "Why should you be mad at a jerk who does what a jerk supposed to do?"

Got it?
(I like dog. No offense to dogs.)