Freud said dream is a royal road to unconscious. In order to study of dream as a tool of understanding unconscious, the author reviewed freud's dream and his technique of dream interpretation. And author reviewed Freud's longing for Rome. Freud longed far Rome but somehow he couldn't enter Rome until he was 45 years old. Through his serf-analysis, he found out that it was because he identified himself with Hannibal since his childhood. When he was about ten, he was told by his father that even though his father had been insulted by an anti-Semite, christian, he hadn't fought back, which caused Freud to identify himself with Hannibal who took vengeance on the Romans. Freud couldn't enter Rome because he unconsciously thought he had the same fate as Hannibal. Here we can see that childhood experiences have influence on the mental life of adults. To put it again in a psychoanalytic term, we can see a ‘child-within’. Even though Freud had the insight that the relationship between himself and Rome resulted from this neurotic identification, he had to wait four years before he could actually bring himself to visit Rome. At the resort, he left for Rome immediately after he bravely fought against anti-Semites who had tormented his sons. This phenomena shows that insights alone cannot bring about changes in behavior. The treatment might be completed after a successful trial manifests the insights in real life.