The Delphic Oracle said no-one was wiser than Socrates; Socrates thought he wasn't wise, but came to understand that although no-one else was either, only he knew that he knew nothing. In epistemology (theory of knowledge) class at uni (philosophy course) once I said to the lecturer that I knew nothing. I really believed I knew nothing for certain. He said, not very charitably, "Don't you know your name?". Luckily no-one said that to Socrates. Well, maybe they did.
Although thinking about that now, the Oracle only said that no-one was wiser than Socrates, which is compatible with all men being fools equally. And the Oracle did give similarly veiled, tricky prophecies:
"Croesus...asked if he should make war on the Persians and if he should take to himself any allied force. The oracles to whom he sent this question included those at Delphi and Thebes. Both oracles gave the same response, that if Croesus made war on the Persians, he would destroy a mighty empire...However, it was his empire, not that of the Persians, that was defeated, fulfilling the prophecy but not his interpretation of it."
https://en.wikipedia.org/wiki/List_of_oracular_statements_fr...