Three yogi hermits are doing a meditative vigil in a cave. One day there's a sound outside the cave. Six months later, one of the yogis says, "That was a goat." The cave is silent once again. About a year later, another yogi says, "That wasn't a goat, that was a mule." Again, the cave falls silent. About two years later the third yogi says, "If you two don't stop arguing, I'm leaving."