Winston's dreams are significant for a few reasons. His dreams of Golden Country are foreshadowing events to come, the time he spends with Julia in the country consummating their relationship and changing his hate for her into some form of love. When they go for a walk and he looks out of the woods over the horizon he recognizes the place immediately from is dream. His dreams of "we will meet in the place where there is no darkness"also foreshadow the time that Winston will spend in the Ministry of Love. When he meets with O'Brien he realizes that the whispers were coming from him. Winston believed at first that the place was some higher plane of understanding or a place in which he would truly be free. He comes to know that the place where there is no darkness is the Ministry of Love. Winston also dreams of his childhood and it gives us, the reader, some insight into the world before the year 1984. This is all the history that Winston knows for certain took place. Winston also dreams of his greatest fear, rats. At first it is simply a dark dream, but as the dreams progress he recognizes his fear in its most pure form. Winston's dreams are the only place in which he feels he is truly free and he learns that even Big Brother can touch his dreams when he is in the Ministry of Love and his dreams of the rats are fully realized and materialized.
Note: foreshadowing are the hints or clues in a literary work that suggest what might occur later