What is the origin of the idiom "nine day wonder" and when to use it?

The idiom "nine day wonder" refers to something or someone that generates a lot of interest or excitement initially but quickly loses its appeal and is forgotten soon after. The origin of this phrase is unclear, but it's believed to have originated in the 16th century when a popular entertainment in England was the "nine days' wonder," which referred to a traveling show or exhibition that lasted for nine days and then disappeared. The term was later used to describe anything that was short-lived and generated only temporary interest or excitement. Today, the idiom is still used to describe things that are quickly forgotten or no longer fashionable after a brief period of popularity.