The Second Story Of Echo And Narcissus

Are you listening closely?

This is the story you know:

"Narcissus was a man who was so in love with himself that he fell in love with his own reflection.   No one else was good enough for him.  He stared into the pool, and eventually wasted away."

But that's not the whole story.

When Narcissus was born his mother, Liriope, took him to the blind seer Tiresias and asked him for a prophecy: "will he have a long life?"

Before Tiresias became a prophet he had spent seven confusing years as a woman, and made two important discoveries about women.  First, that women get more pleasure from love making than men.  When he told this discovery to Hera and Zeus, Hera, in a rage, struck him blind, which lead to his second discovery: not all women want to hear this. 

Zeus tried to make up for his blindness by giving him the power to know the future.
So Tiresias gave Liriope his cryptic prophecy:

"He'll have a long life as long as he never knows himself."

Now what could that mean?