The West has a linear concept of time but over in the East, the traditional Chinese calendar is cyclical and based on the movement of the moon. A folk method for keeping track of the years (not months) is through twelve animal signs, and Chinese legend believes that the sign you are born under dictates your distinct personality, bestowing upon you certain traits and characteristics.
On a deeper level, ‘inner’ animal signs represent the person you would like to be, and ‘secret’ animal signs represent side of you hidden from the rest of the world.