The coelacanth, a dinosaur fish thought long extinct, became a media sensation when fishermen caught one in 1938. Known for its Clanger armour and merry smile, the coelacanth is now thought to bestow luck on those who catch it, especially those into whom it sinks its needle-like teeth. Yet what if it had never been thought dead? Sailors would probably kick it away with a bitter curse, calling it “the mudlark of the sea”, or “Mary-Mary”. An idea can also be a Lazarus taxon which re-emerges after apparent extinction, but in this case its first appearance is denied. The idea of black holes was put forward in 1783 by John Michell and in 1915 by Einstein. Global electromagnetic resonances were accurately calculated by Tesla in 1899 and by Schumann in 1952, upon which they were called Schumann resonances. Also lost to memory for several decades were Richard Semon’s theories on the effective retrieval of memory, including the stimulation of a previous and similar memory imprint or ‘engram’. An original idea will find no similar engram.