Narcissus was an extremely beautiful man whom every woman who saw him loved him. there was a special woman however who loved him named echo but she was cursed to only speak when spoken to. When she saw him he wouldn't acknowledge him and when he did she just repeated what he said. He looked into a pool of water and finally accepting that he would never love any woman and just stared into the pool until he died. Echo was so sad that she disappeared.
The moral of this story is not to fall be to in love with yourself or else you won't have good relationships with others.
The worldly connection is that the word narcissism (being in love with your self) comes from his name.