“Foolish people deny the existence of the soul, but it is a fact that when we sleep we forget the identity of the material body and when we awake we forget the identity of the subtle body. In other words, while sleeping we forget the activities of the gross body, and when active in the gross body we forget the activities of sleeping.” (Shrila Prabhupada, Shrimad Bhagavatam, 4.29.71 Purport)