Language

Apo- A prefix from a Greek preposition. It usually signifies from, away from, off, or asunder, separate; as, in apocope (a cutting off), apostate, apostle (one sent away), apocarpous. -from thinkexist.com

Meta- "Meta- (from Greek: μετά = "after", "beyond", "with", "adjacent", "self"), is a prefix used in English (and other Greek-owing languages) to indicate a concept which is an abstraction from another concept, used to complete or add to the latter." - from Wiki.
Basically, an X about X.
Metacognition- Thinking about thinking

Greek culture has influenced our society in so many ways we cannot imagine: fundamental principles of democracy, art (discovery of foreshortening), language, to name a few. I think I want to venture into Greek mythology soon. (: