The Story of Echo and Narcissus
Echo was a lovely nymph who loved to talk. Once, she incurred the wrath of Hera and was punished to never be able to speak again, except to repeat the last words of others. One day, she saw the beautiful youth Narcissus and fell deeply in love with him. Alas, she couldn't speak to him, nor could she tell him of her love! Thus, quietly, she followed him. When he discovered her, and spoke to her, Echo could, but repeat his last words in response. Thinking that she had mocked him, Narcissus dismissed her coldly and asked to be left alone. Heartbroken, Echo pined away to the mountains where she continued to repeat the last words of others. Narcissus, when taking a drink by a stream, chanced upon his reflection in the clear water, and thinking it was a beautiful water-nymph, fell in love with himself. In vain he begged the nymph to come to him! He wouldn't eat, for he cannot bear to go away from the beautiful nymph; he couldn't drink, for if he reached out to the water, the nymph would disappear; eventually, he died pining for his own reflection. At the spot where he lay, sprung flowers, named narcissus, which loved nothing better than to gaze at the reflections of own pretty selves in the water.
Thus, is the myth from which narcissism originated, and the term describes a person who loves and admires himself excessively.