"How can the mind which has created the world accept it as unreal? That is the significance of the comparison made between the world of the waking state and the dream world. Both are creations of (imagined within) the mind, and so long as the mind is engrossed in either, it finds itself unable to deny their reality.
It cannot deny the reality of the dream world while it is dreaming, and it cannot deny the reality of the waking world while it is awake. If, on the other hand, you draw your hand completely from the world, and turn it within and abide there, that is, if you always keep awake to the Self (consciousness) which is the substratum (source) of all experiences, you will find the world of which you are now aware is just as unreal as the world in which you lived in your dream (during sleep at night).”
~Sri Ramana Maharshi (From the “Maharshi’s Gospel”, Chapter III, “The Jnani and the World”)