The story of Cassandra, the woman who told the truth but was not believed, is not nearly as embedded in our culture as that of the Boy Who Cried Wolf — that is, the boy who was believed the first few times he told the same lie. Perhaps it should be. The daughter of the king of Troy, Cassandra was cursed with the gift of accurate prophecies no one heeded; her people thought she was both crazy and a liar and, in some accounts, locked her up before Agamemnon turned her into a concubine who was casually slain along with…