A person's life is influenced by rhythmic biological cycles that can effect his or her ability in various ways, such as mental, physical and emotional activity. These cycles begin at birth in a steady (shine wave) throughout life, and by modeling them mathematically, it is suggested that a person's level of ability in each of these domains can be predicted from day to day.
The moon sign is your emotional life, love and romance. It relates to immediate emotional responses. The influence of the Moon is more your feelings and your subconscious self. It shows how you react to thoes around you. The moon sign shows a considerably different side of your nature, a side run by emotions.
You know your sun sign but now you will understand why each sun sign can reflect such observable traits and yet still come in so many varieties.