I saw this in 1974 when asked by a girlfriend to see it with her. She had been so scared the first time that she saw it, she had left and then needed to return to see it through. She wanted me to go with her for support. Scary movies were not my thing, but I went with her and thought it quite a good movie. In 1995, I bought it on DVD and saw it again, and again, and again. I found it deeply moving, not so much for Reagan and the satanic spirit, but for the relationship between the older priest and the younger priest. The older priest had lived a full life and knew of things that could not be taught. The younger priest possessed no faith, and thought the whole exercise unbelieveable. During the course of the movie, the younger priest experiences a transformation. This spiritual transformation is the real subject of the movie. If a myth is a fictional story which reveals a deeper truth, then this is a very powerful myth about spiritual transformation, regardless whether you believe in satan, exorcisms, religion or whatever. The accompanying commentary must be heard to fully appreciate the depth of this film. Personally, this is an all-time top ten movie.