"Q: In sleep there is neither the known, nor the knower. What keeps the body sensitive and receptive? M: Surely you cannot say the knower was absent. The experience of things and thoughts was not there, that is all. But the absence of experience too is experience. It is like entering a dark room and saying: 'I see nothing'. A man blind from birth knows not what darkness means. Similarly, only the knower knows that he does not know. Sleep is merely a lapse in memory. Life goes on."