Letters are commonplace enough, yet what splendid things they are! When someone is in a distant province and one is worried about him, and then a letter suddenly arrives, it is as though one were seeing him face to face. Again, it is a great comfort to have expressed one's feelings in a letter even though one knows it cannot yet have arrived. If letters did not exist, what dark depressions would come over one! When one has been worrying about something and wants to tell a certain person about it, what a relief it is to put it all down in a letter! Still greater is one's joy when a reply arrives. At that moment a letter really seems like an elixir of life.
-- from The Pillow Book of Sei Shonagon, circa late 900s. Translation by Ivan Morris.