Sleep, dream and waking are only modes passing before the Self. They proceed whether you are aware or not.

Devotee:  We have to deal with a physical body in a physical waking world. If we sleep while work is done or work when sleep overtakes us, the work will go wrong.

Ramana Maharishi:  Sleep is not ignorance; it is your pure state. Wakefulness is not knowledge; it is ignorance. There is full awareness in sleep; there is total ignorance in waking. Your real nature covers both, and extends beyond. The Self is beyond knowledge and ignorance. Sleep, dream and waking are only modes passing before the Self. They proceed whether you are aware or not. That is the state of the Jnani in whom pass the states of waking, samadhi, deep sleep and dream, like the bulls moving, standing or being unyoked when the passenger is asleep as aforesaid. These questions are from the point of view of the ajnani; otherwise these questions do not arise.