You are in a desert. A lion, a cow, a horse, a sheep, and a monkey. To escape the desert you are going to have to get rid of one of your animals. You have 4 animals left. It goes on for miles.
Sand is everywhere.
You realize, to get out, you are going to have drop another animal. You have 3 animals left. Walk, walk, walk. Hot, hot, hot. You have no choice but to drop another animal.