The noun narcissist refers to someone intensely concerned with only his or her own self or interests and who seems to forget that others exist.
The noun narcissist today means someone only concerned with his or her own interests or predicament and its origin is from Greek mythology. Narcissus was a hunter who was exceptionally beautiful and also just as proud of his looks, ignoring other people around him. He was punished by the gods by falling in love with his own reflection in a pool of water. Not realizing it was himself he loved, he eventually died from unrequited love.