In what ways is Oedipus' downfall not a total loss? What can be gained from his story?

The tragic hero such as Oedipus always discovers something about himself. He achieves reversal and recognition at the same time. He knows that he has "killed his father and married his mother" and knows that he has also created his own punishment. He has learned that the oracle was right, that he cannot escape his fate even though he tried to, and he knows that he must now leave Thebes and his children. This is what was predicted and he finds out that this prediction comes true.