The Self is changeless. It is the ego that has come between.

Devotee:  I do not know if the Self is different from the ego.

Ramana Maharishi:  How were you in your deep sleep?

Devotee:  I do not know.

Ramana Maharishi:  Who does not know? Is it not the waking Self? Do you deny your existence in your deep sleep?

Devotee:  I was and I am; but I do not know who was in deep sleep.

Ramana Maharishi:  Exactly. The man awake says that he did not know anything in the state of sleep. Now he sees the objects and knows that he is there; whereas in deep sleep there were no objects, no spectator, etc. The same one who is now speaking was in deep sleep also. What is the difference between these two states? There are objects and play of senses now which were not in sleep. A new entity, the ego, has risen up in the meantime, it plays through the senses, sees the objects, confounds itself with the body and says that the Self is the ego. In reality, what was in deep sleep continues to exist now too. The Self is changeless. It is the ego that has come between. That which rises and sets is the ego; that which remains changeless is the Self.