Trivia: To prevent something from coming true, you can knock on what?
Correct Answer: Wood
So why is this answer correct? : This superstition is so common that some don’t even realize they do it. Knocking on wood is supposed to prevent whatever was said aloud from coming true. Different theories persist regarding the origin of the practice, but some historians think the practice emerged in the 19th century when children in England played a game called Tiggy Touchwood. It was basically a version of tag, but if you touched wood, you had immunity from being caught.