The ancient Greeks, and later the Romans, had a complex religious and mythological system. What most people don't realize is that educated people living in those times didn't believe very much of that stuff. Its much like the attitude some people have toward contemporary religion--they pick the parts they like but, when pressed, don't have much confidence in the details.
Among the more widely accepted beliefs, however, concerned the Oracle at Delphi, located at the site of the omphalos (the center of the world) from the 9th century BC, where messages from Apollo were relayed through the Pythia (a kind of spokesperson who uttered trance-like messages that were interpreted into prophetic statements).
Once in the 5th century BC the question before the Oracle was who, among all men, was the wisest? The pronouncement came that Socrates, the Athenian philosopher, was truly wisest.
Socrates was told of this event and he replied,
"If Apollo has said that I am wisest, then I must believe it. But if it is true then it is because I alone, of all the Greeks, realize that I know nothing."
--------------- A Final Thought ...
"Well I am certainly wiser than this man. It is only too likely that neither of us has any knowledge to boast of; but he thinks that he knows something which he does not know, whereas I am quite conscious of my ignorance. At any rate it seems that I am wiser than he is to this small extent, that I do not think that I know what I do not know."
- Socrates (469-399 B.C.), Greek (Athenian) philosopher. Quoted in: Plato, Apology, sct. 19, of “a gentleman with a reputation for wisdom.”