Ghosts. When someone utters that word, what do you think of? Costumed children running around with sheets over their heads? A cartoonish figure, waving its arms around and shouting ‘Boo!’ at everything that moves? A silly spirit, doing every sort of mischief upon the living? The ghosts of campfire tales: tortured beings who haunt dark places, moaning of great sadness or a life unlived? Or perhaps your thoughts turn towards the more serious implications of the word. “Ghost” could refer to a lingering memory, one which refuses to cease its haunt on your consciousness.