Consciousness; awareness, attention, the sense of I am, the observer and the observed, all of it vanish at night and comes back in the morning. A doctor can put you to sleep in a second before an operation. And then he wakes you up again after the operation. A good hypnotist can do the same thing only by using words. Consciousness is very flimsy.
Consciousness comes and goes; presence, the now, awareness, attention, awakenings, thoughts, discipline, love, joy, suffering, the sense of I am, meaning, everything comes and goes.