main idea of i am legend

A central theme, as the title suggests, is the nature of legends. Legends are often based on real persons or events, but enlarged through retelling to achieve mythic proportions. They are a blend of fact and fiction, and if well known, become a part of a cultural heritage. The legendary hero is usually set apart from his contemporaries by possessing some special qualities, such as great strength or magical abilities. In I Am Legend, much of what Robert knows or assumes about vampires comes from traditional or legendary lore, yet the legend has now become scientifically documented. In a study in symmetry, Robert eventually passes from a real person to a legend, the last of his kind. The symmetry is further shown in that Robert has modeled his behavior from Van Helsing, a vampire-fighter of legendary fame.