Personification of "Oblivion", daughter of Eris, is one of the rivers which flow through Underworld. The souls of the dead had to drink from it to forget their past lives spent on earth
in ancient Greek mythology, a river in Hades (=the place under the ground where the spirits of dead people are supposed to live) . When people who have died drink its water, they forget everything that happened when they were alive. Ancient Greek personification of oblivion. She was the daughter of Eris (Strife). Her name was also applied to a river or plain in the realm of the dead. In the Orphic mysteries it was believed that the newly dead who drank from the River Lethe would lose all memory of their past existence. The initiated were taught to drink instead from Mnemosyne, the river of Memory