Milton, Rivers of Darkness
From "Paradise Lost"
Abhorred styx, the flood of deadly hate,
Sad Acheron of sorrow black and deep;
Cocytus named of lamentation loud
Heard on the rueful stream; fierce phlegethon
Whose waves of torrent fire inflame with rage
Far off from these a slow and silent stream,
Lethe, the river of oblivion;, rolls
Her watery labyrinth, where of who drinks
Forthwith his former state and being forgets,
Forgets both joy and grief, pleasure and pain
Lethe on the Earth ��μ�
According to the ancient Greek Roman mythology, there are five rivers that flow through the Hades, the underground world where people arrive after their death. The last river, Lethe, is the most important river among the five. After passing the Lethe, people "Forgets both joy and grief, pleasure and pain" just as Milton said. They can not comeback to the world of lives after passing the river Lethe. The word lethargic also is derived from the Lethe, the river of oblivion. However, Lethe does not exist only in the Hades but it also exists on the world we are living on.
There is certain point when you can not come back to the former state. Especially between the human relationships, there exists Lethe. When, suddenly one feels alienated from one's friend, one should aware that they already has passed each other's Lethe.
There is nothing like permanency. People keep changing and so does the world. One of the famous Korean poet during the Jo-Sun dynasty, Yoon Sun Do, wrote the poem "the song for five friends". In his poem, he mentioned about five permanent friends, which are rock, star, pine tree, bamboo and river. However, they also change. Rock will wear our by aeration, star will collapse within thousands and millions of light years, pine tree and bamboo will wither in thousand's of years and river will stop flowing when the rain stops falling for years. For my perspective, there is nothing like permanency. Human relation also can not be permanent and that makes our lives happy, sad, dangerous or adventurous.
If the Lethe continues to exist in one's mind, one can not expect the permanency. There can not be true friendship or love. However, one thing that rarely happens is the interconnection of Lethe between the two. Then you become I and I become you. The world of Matrix is established between those two with connected Lethe.