The irony lies in how Oedipus' actions, driven by his desire to discover his true identity and escape the ominous prophecy, ultimately become the means by which the curse is fulfilled. Oedipus' quest for the truth leads him to the revelation that the man he believes is his father is not truly his parent.
However, in the process of uncovering this truth, Oedipus unknowingly kills his biological father, Laius, and marries his mother, Jocasta, fulfilling the prophecy. This series of ironic events highlights the inescapable nature of fate and the power of divine retribution in Greek tragedy.