It seems fitting that Franz Kafka cut short his vacation to rush to the Louvre to be a part of this event that could have been described as Kafkaesque. Of course any reputable country music artist could tell you that songs focusing on what is missing hold our attention.
This suggests the possibility of opening a museum of lost objects. (For one thing, acquisition costs would be incredibly low.)
Within the museum could be rooms of empty space, each blank space a tribute to lost art or literature. The Greek tragedian Sophocles produced about 120 plays, only seven of which have survived into modern times. "The scholar Didymus of Alexandria earned the nickname 'Bronze-Ass' for having what it took to write more than 3,500 books; apart from a few fragments, all have vanished."* Of the seven ancient wonders, only the Great Pyramid remains. What we now have saved in traditional museums is just a fraction of the great works that existed once upon a time. There are hundreds of museums filled with items that have been "found." This museum of what has gone missing would be the one museum that could be labeled "lost."
Perhaps along one wall of this special section of what is missing could be a place where people - along the lines of PostSecret - wrote down some of their deepest losses, from opportunities to great loves to being able to run without aches. It might just be that people would line up to see that.
* pp. 81-2 of Stephen Greenblatt's The Swerve: How the World Became Modern