The national flag of Greece and the flag of the European Union fly above a government building ahead of the general election on Sunday on January 23, 2015 in Athens, Greece.
If you've been following the Greek financial crisis, you've certainly seen this old cliche in the headlines.
We're all guilty of it. Even NPR had "If the mess in Greece is all Greek to you, then read this."
Shakespeare lovers are well aware this phrase comes from The Bard — or, well, partly.
Ben Zimmer, a language columnist for the Wall Street Journal, says Shakespeare is probably responsible for the popularity of the phrase.
"It appears in his play Julius Caesar," he says. "There's a character who's describing the speech of Cicero, who is a learned scholar; he actually knew Greek. But this character didn't really understand what Cicero was saying, and he says, 'For mine own part, it was Greek to me.' "
But Shakespeare didn't actually come up with "It's Greek to me." The phrase appeared in a translation of an Italian play decades earlier.
Its true origin is a bit of a mystery, though Zimmer says there's a pretty good guess. Back in the days before the printing press, medieval monks would copy old Latin manuscripts to preserve them, but the Greek alphabet threw them for a loop.
"And so if they were copying a Latin manuscript, and they came across a Greek quotation in a manuscript, they might have trouble actually trying to copy that part," Zimmer says. "And so as a kind of a cop-out, they might just write in Latin, Graecum est, non legitur, which means, 'This is Greek. It cannot be read.' "
But it seems like those medieval monks — or whoever's behind "It's all Greek to me" — were just expressing a universal human sentiment.
Zimmer says there's a version of this phrase in many languages.
"In Finnish, you might say, 'It's all Hebrew,' " he says. "In Italian, you might say, 'This is Arabic, or this is Aramaic to me."
And in Greek? The expression is, "This is all Chinese to me."