nine days' wonder

The whole winter did this state of things continue, until the At Home days at Ye Dene were no longer a nine days’ wonder but an established fact.

From The Little Vanities of Mrs. Whittaker A Novel by John Strange Winter

The duel between Sir Maxwell Danby and Leslie Travers was a nine days' wonder.

From Her Season in Bath A Story of Bygone Days by Emma Marshall

—Did any particular circumstance give rise to the saying, "A nine days' wonder?"

From Notes and Queries, Vol. IV, Number 98, September 13, 1851 A Medium of Inter-communication for Literary Men, Artists, Antiquaries, Genealogists, etc. by Various

The engagement had been a veritable nine days’ wonder.

From An Unknown Lover by Mrs. George de Horne Vaizey

At the college it was a nine days' wonder, but I let them wonder.

From In Accordance with the Evidence by Oliver [pseud.] Onions