The prophet said that he would slay his own father and have children with his mother, and he had no idea that Jocasta and Laius were his real parents. He was trying to avoid his "adoptive" parents, the king and queen of Corinth, but little did he know he was avoiding the wrong people.

When he killed Laius, he had no idea that he was the king of Thebes, let alone his biological father. And so if he did not know that Laius was the king of Thebes and his biological father, how was he to know that Jocasta was his mother?

Oedipus was definitely blind to everything that he was doing and everything that was going on around him. The prophets are like the people that tell the fate of a person and there is no way that a person can change his/her fate because fate is what is supposed to happen in a person's life, and it simply cannot be changed.

I believe that when Oedipus actually found out who his parents really were, he was too hard on himself and that the punishment given was much too harsh since he could not help what was to happen. He didn't do anything on purpose and it doesn't seem like anyone considered that before he was banished from the kingdom.

It is disgusting when you sleep with your own mother,  but he had no idea it was his real mother in the first place. Killing anyone is inhuman, let alone killing your own father, but he again had no idea that the man that he had killed was his own father. He had not even considered these, since he had no idea that the king and queen of Corinth were not his real parents. It wasn't until it was too late that he learned of where he really came from.

Slay: If he only kills one man during his lifetime, wouldn't he suspect that somehow the man was his father?  True, he has just left the oracle and believes he is sparing the parents who raised him--and he's having a bad day, having also just given up the kingdom he would have assumed that was destined to rule--Corinth.  So when he's attacked, his temper flares, but he's a chip of the Grecian block, since Laius angrily told his charioteer to run the stranger down. 

No idea: So what would a royal chariot and entourage look like as it came up the road away from Thebes?  How did Laius get out of town, anyway?  Wasn't the sphinx attacking all travelers with the riddle, devouring all who failed to answer it correctly?  The sphinx is, then, a tool of the gods in enforcing the fate/curse of this family.

Mother: Here's the biggie.  If a prophecy says that you're going to kill your father and marry your mother--and you've recently killed a guy, guess who that older woman is standing in front of you offering you her recently deceased husband's throne. Run!

But Oedipus arrogantly assumes that he has handled the problem by fleeing his parents in Corinth--and besides, the oracle has just cheated him out of one throne, so what's the harm in taking Thebes instead?

He didn't do it on purpose:  When someone sideswipes your car because they weren't being cautious enough or even watching their driving, does the insurance company pay less because it was not a deliberate attack?  No, but the driver isn't hauled away by the police for attempted murder, either.  Oedipus declared what the punishment would be for the killer of Laius, and to his credit he sticks to that decree when he finally pins down that it was him.

Bads, but not his bads:  "Assumption is the mother of all mistakes" once said a villain in a Steven Segal movie (the one on the train), and so it is with Oedipus.  But his assumption is arrogant because it places him in a position to oppose the gods successfully.  Maybe Ulysses could avoid getting killed by Neptune on the way home, but his death wasn't foretold.  What man, even a heroic man of action like Oedipus, can escape fate?  In fact, what is fate except the prediction of what a family will do, given their personalities, in a given crisis?