Does an enlightened person ever dream?
No, an enlightened person cannot dream and if you like dreams very much, never become enlightened. Beware! dreaming is part of sleep. The first thing is that for dreaming to happen you have to move into sleep. For ordinary dreams you have to move into sleep. In sleep you become unconscious when you are unconscious, dreams can happen. They happen only in your unconsciousness.
An enlightened person is conscious even while asleep. He cannot become unconscious. Even if you give him an aesthetic, chloroform or something like that - only his periphery goes to sleep. He remains conscious; his consciousness cannot be disturbed.
Krishna says in the Gita that while everyone is asleep the Yogi is awake. It is not that Yogis are not going to sleep in the night; they also sleep, but t heir sleep has a different quality. Only their bodies sleep, and then their sleep is beautiful. It is a rest.
Your sleep is not a rest. It may even be an exertion, and in the morning you may feel more exhausted than you ever felt in the evening. A whole night's sleep, and in the morning you feel more exhausted - what is happening? You are a miracle!
The whole night was in an inner turmoil. Your body was not at rest because you mind was so active. And the activity of the mind is bound to be an exertion for the body, because without the body the mind cannot act. The activity of the mind means parallel activity of the body, so the whole night your body is moving and is active. that is why in the morning you feel more exhausted.
What does it means for someone to become enlightened? it means one thing; now he is perfectly conscious. What so ever goes on his mind he is aware. And the moment you are aware, certain things completely stop. Just through awareness they stop. It is just like this room is dark and bring a candle: the darkness will disappear. Everything will not disappear; these bookcases will be here and if we are sitting here we will be here. By bringing the candle only darkness disappear.
When someone becomes enlightened now he has and inner light. That inner light is awareness. Through that awareness sleep disappears - nothing else. But because sleep disappear, the quality of everything changes. Now what so ever he is doing to do will be in his perfect alertness, and that which needs unconsciousness as a prerequisite now becomes impossible.