Breaking a Mirror
According to another belief, breaking a mirror brings seven years of bad luck. If a mirror breaks, you must take the pieces out of the house quickly and bury them. Before the invention of mirrors, people must have first seen their own images in water; it meant that bad luck would follow. When glass mirrors came into use, the bad luck became associated with breaking a mirror, rather than with the movement of water. It was believed that the person's image was shattered when the mirror broke. Historians think that the number seven might have come from a Roman belief. The Romans thought that a person's body renews itself every seven years.