Today's picture shows a prospector and his donkey. The picture was taken during the gold rush of the early 1900's in Grant's Pass, Oregon.
The donkey has developed a reputation as a very stubborn animal. My understanding is, that in fact, the donkey is actually very intelligent, and must be worked with differently than other animals. Rather than simply teach the donkey to do what you say, you more or less have to work things out with the donkey. Once you reach an understanding, things will go smoothly.