What does all Greek to really mean?

"All Greek to me" is a phrase used to describe something that is completely incomprehensible or difficult to understand. It is often used to describe a foreign language or a complex subject that is beyond one's knowledge or experience.

The phrase is derived from the fact that ancient Greek was the primary language of learning and scholarship in Europe during the Renaissance. At the time, Greek was not widely spoken or understood by the general population. As a result, many people found it difficult to understand texts and conversations in Greek.