In his bleak novel, The Unbearable Lightness of Being, Milan Kundera sets out to explain the insignificance of our existence, which results from the tragic fact we only live once.

He said: "What happens but once, might as well not have happened at all. If we only have one life to live we might as well not have lived at all." Or to use his more snappy German phrase: "Einmal ist keinmal."