Myth of Narcissus 
When Narcissus was born of the River god Cephisus and nymph Liriope, his mother asked the seer Tiresias if he would live a long life.  “If he never knows himself,” was the reply.  He grew up to be a handsome young man, as strikingly beautiful as Dionysus or Apollo.

The nymph Echo fell in love with Narcissus.  However, she had been cursed by Juno for chattering to her to keep Juno from catching her husband cavorting with the other nymphs.  Juno’s curse left Echo only able to repeat back the last words that were spoken to her.

Echo fell in love with Narcissus, but, being a vain young man, he hardly acknowledged her existence.  When Echo tried to flirt with him, he was repulsed by her inability to do more than parrot back his words.

Heartbroken, Echo ran away to the woods to live among the mountains and caves.  There she wasted away from grief and embarrassment.  When she died, she was changed into rocks, and nothing remained but the sound of her voice.

Many other nymphs and young men were the target of Narcissus’s mockery.  One he'd hurt prayed to the gods that although Narcissus would, indeed, greatly love himself, he would never win that which he so desired.

As punishment for his callous treatment of Echo, Nemesis required Narcissus to stare at his own image in a pond.  Seeing his own handsome reflection looking back, Narcissus mistook the “other” for a water sprite.  Entranced, Narcissus fell in love with this reflection—its lovely eyes, beautiful hair, handsome body.  But when he reached into the water to embrace this lovely image, it fled.

Entranced, he couldn't bring himself to leave the pool, imploring his reflection to return his affection.  Yet, when he wept over the pool, his tears broke the pool’s surface, causing the lovely image to vanish.

When the "water sprite" didn't return his love, Narcissus was so distraught that he pined away, dying of sorrow beside the pool that held his unresponsive reflection.

Although Narcissus had treated them badly, all the nymphs were deeply grieved at his death . . . even Echo.  When they prepared his funeral pyre, no one could not find his body, so they placed a flower on the bonfire it in his place . . . the flower that we now know as the narcissus.

Some say that Narcissus still looks at his reflection in the waters of the River Styx, which flows through the Underworld.

It's not surprising that the disorder whose primary characteristics are a pattern of grandiosity, a great need for admiration, and a lack of empathy bears his name.

NOTE:  Accounts of Narcissus and Echo are given in Ovid’s Metamorphoses1 and Bulfinch’s Mythology2.

1Ovid, 1976
2Bulfinch, 1998