conuly

Knocking on wood is a myth. Actually, it's a mutated idea done by people who forgot why they were doing on it. The idea was you knocked on trees, wood generally being in tree form. This was because spirits lived in the trees. Knocking on dead wood, such as a table is pretty silly.

Although I have heard the argument made that spirits have probably modernized their living space and it might make sense these days to knock on plastic.