An intellectual exercise in watching paint dry, “It Did It” flew towards left field and right over my head, but I think that was the intention. This slow mediation of the effects on someone who goes off Prozac (basically the filmmaker) is interesting, utilizing the scientific method to tell the story. Yet the film is so slow and methodical you probably won’t care when you get to the end. It seems all the more self-indulgent when you know that the filmmaker is basically talking about himself — I failed to see the point of it all.