User blog comment:Himeyuka/Reyna and Hylla's past/@comment-3146930-20111209131828

We have been shown that there is more than one way to lose your memory (River Lethe, Memory stolen, the Lotus Hotel makes you forget the outside world in a way). Circe's island could make you forget things after a certain amount of time to try and get you to stay their forever. Even if they left the island, some of the finer details of their past could be lost or possibly if they stayed on the island long enough, they naturally forgot depending on how long they were there