Explanation: King Croesus of Lydia (located in what-is-now Turkiye) was once supposedly told by the Oracle of Delphi in Greece that, should he cross the river dividing his land from the Persians, "a great empire will be destroyed." With that in mind, he went to war with the utmost confidence in his success. It had, after all, been foretold by the Oracle!
... King Croesus's empire was destroyed by the war. Maybe being cocksure isn't a replacement for a functioning brain?
Gotta be careful about them seers and their wording.
... the uh... timing of this meme and our current war with Persia has me a little triggered.