The twenty-first guru was the snake which taught two things. One was to abandon crowds. The second was that familiarity and the known blunt awareness and create attachment.
The lesson also applies to the mind. Shun the crowds within oneself, the market place within, and move closer to an uncluttered state of consciousness. Do not hold on to anything known, whether a thought, or an emotion. This will help the sadhak keep his awareness totally in every moment, unconditioned by yesterdays.
A snake that makes no hole for itself, but who rests in holes other creatures have abandoned, or curls up in the hollow of a tree for a while, and then moves on. From this snake, I learned to adjust myself to my environment and enjoy the resources of nature without encumbering myself with a permanent home. Creatures in nature move constantly, continually abandoning their previous dwellings. Therefore, while floating along the current of nature, I find plenty of places to rest. Once I am rested, I move on. (Source: The Himalayan Masters: A Living Tradition by Pandit Rajmani Tigunait, PhD.)