I've watched this movie countless times. My first viewing being when I was a young child and I can comfortably say this is a masterpiece amongst masterpieces. This movie is by no means perfect but the aesthetic alone along with the score make it easily unforgettable. Personally I find horror movies now and days to be phoned in, simple scares that aren't meant to stick with viewers after their viewing experience. What makes a masterpiece in horror though is a piece of work that sits with the viewer well after the film is over. Looking into the director himself and reviewing the monologue in this film with the older professor character you really start to believe this is what Dario Argento believes and that's why this film will live forever on in my head. Great cinematography, beautiful score, and a compelling narrative to really sit and think about.