In athletics, wearing a "lucky sock" or "lucky band" is seen to believe that the athlete's performance will be improved due to the special clothing worn. Before taking a test, some students tie their shoes a certain way or even keep a lucky item in their pocket to "ensure" a good grade. The most general and popular form of superstition today, however, is to perform certain actions to receive good luck in any way, shape, or form. Examples of this include picking up a penny "warning", avoiding stepping on a crack in the sidewalk, knocking on wood when something is said that could lead to a particular bad fate, looking away when a black cat is spotted on the street. , and stay home on Friday the 13th to avoid bad luck at all costs. Of course these superstitions have probably been modified as they have been passed down year after year, but that's the beauty of time: you can look into the past and see how many things have changed over the many years.