Two cowboys are riding their horses together on the prairie. They come upon a big pile of manure. The first cowboy goes to the second, "I will bet you a $1000 that I can eat all of this crap." The second cowboy agrees, so the first cowboy eats the entire pile and wins $1000.

The two cowboys ride on and after some time come across another pile of manure. This time the second cowboy bets the first that he too can eat the whole pile for $1000. The first cowboy agrees and the second cowboy eats the entire pile and wins the bet.

They ride on again. After a while the first cowboy says to the second, "Do you realize that we just ate a whole pile of manure for nothing?"