The Rosetta Stone is written in three scripts because when it was written, there were three scripts being used in Egypt. The first was hieroglyphic which was the script used for important or religious documents. Detail of hieroglyphic and demotic script on the Rosetta Stone.
The Texas Chainsaw Massacre never happened in real life. The filmmakers just wanted people to think it was a true story, so more people would go see the movie. It was also a bit of a joke on their part, to see if people would believe it was real.
Texas Chainsaw Massacre is the quintessential horror movie of all time, and along with Night of the Living Dead and The Exorcist helped establish the modern era of horror. Gunnar Hansen's performance as Leatherface would eventually serve as the prototype for many of the slashers of the late 70's and early 80's.