It happened once upon a time that a guru was attempting to teach a student something about the higher knowledge. The guru was seated with his back against a stone wall, and the student was facing him. Unfortunately, the student was not yet ready for the higher knowledge, and his attention was focused instead on a small mouse that was climbing on the wall behind the guru’s head.

Then the mouse found a hole in the wall, and began to creep inside it, leaving only the tail hanging out. At this point, the guru, noting the disciple’s inattention, said sharply, “Are you listening? Has anything gone in?”

“Yes, guru-ji,” the student replied quickly. “Everything has gone in but the tail.”