Quote from : The Battle of the Labyrinth Book

They send a person who can never stay," she whispered. "Who can never accept my offer of companionship for more than a little while. They send me a hero I can't help ... just the sort of person I can't help falling in love with." ... As I sailed into the lake I realized the Fates really were cruel. They sent Calypso someone she couldn't help but love. But it worked both ways. For the rest of my life I would be thinking about her. She would always be my biggest what if.