Most people, when they think of constellations, think of big dipper and little dipper. They may even think of the horoscope, the zodiac constellations. However, there are so many more than just that, everything from the bird of paradise Apus to a chisel called Caelum. My sign, for example, has a mythical background related to a pair of twins called Castor and Pollux (Sarah's sign as well, we're both Geminis).
Horoscope is one of the very first personality predictors in human history. It's no Carl Jung but it gives us a baseline peek into who we are and as creatures of curiosity we are always looking inward as much as we are looking upward (sic to the stars, our roots?) and outward (to each other, our fellow star dust buddies?).