From Greek mythology. It's from the story of Echo and Narcissus; Narcissus was a handsome young man that fell in love with his own reflection.

A narcissus is a type of flower of the Lily family. Narcissus is especially used to name ones with white flowers. Narcissus can also refer to a young man in Greek mythology that fell in love with his reflection after seeing it in a pool of water. He supposedly transformed into a narcissus flower after death.

Aphrodite caused the beautiful young man, Narcissus, to fall in love with himself.

The word "narcissism", meaning self-love or admiration for ones self, is derived from the story of Narcissus in Greek Mythology. Narcissus was a handsome young man who loved no one but his own reflection.

Narcissus