By reason of the habit-energy stored up by false imagination since beginningless time, this world is subject to change and destruction from moment to moment; it is like a river, a seed, a lamp, wind, a cloud; like a monkey who is always restless, like a fly who is ever in search of unclean things and defiled places, like a fire which is never satisfied. Again, [thought] is like a water-wheel or a machine: it goes on rolling the wheel of transmigration, carrying varieties of bodies and forms... causing the wooden figures to move as a magician moves them. Mahamati, a thorough understanding concerning these phenomena is called comprehending the egolessness of persons.

(The Lankavatara Sutra)