In Knowledge of the Higher Worlds you are advised to imagine things backwards from time to time. A backwards review involves picturing events as if they proceeded in the opposite direction from that in which they proceed in our normal world. Among other things, this picturing backwards gradually builds the spiritual forces that make one capable of entering a world that is the wrong way round when compared with the physical world. That is how the spiritual world is. It reverses many aspects of the physical world. […] People need to prepare for the future by getting accustomed to thinking backwards. Then they will begin to take hold of the spiritual world through this thinking backwards, just as they take hold of the physical world by means of thinking forwards. Our ability to imagine the physical world is a result of the direction of our thinking.
[…] for someone who has gone only a little way beyond the threshold of the spiritual world, it is just as foolish to assert that the world only goes forward, never backward, as it is to say that the sun only goes in one direction and can never return! Of course it comes back along this apparent path on the other side.
Source: Rudolf Steiner – GA 170 – The Riddle of Humanity: LECTURE EIGHT – Dornach, 13th August 1916
Translated by John F. Logan