It's not exactly the Rosetta Stone

Meaning

This phrase means that something is not a crucial key to understanding a complex situation or a difficult problem.

Origin

The Rosetta Stone, a granodiorite stele inscribed with a decree issued at Memphis, Egypt, in 196 BC, holds an unparalleled significance in history. Its unique trilingual inscription—Ancient Egyptian hieroglyphs, Demotic script, and Ancient Greek—provided scholars with the key to deciphering Egyptian hieroglyphs. Before its discovery, the language of the pharaohs was a mystery, locked away in stone for millennia. Therefore, the Rosetta Stone became the ultimate symbol of unlocking profound secrets and understanding the incomprehensible, making any reference to it evoke ultimate clarity and comprehension.