User blog comment:Hazelcats/The Characters of HoO/@comment-3066424-20101107045811/@comment-3146930-20101108072204

Maybe when the gods are in their Roman/Greek forms, they can keep information from their other personality. That may be why not even Artemis knows where Percy is. Also, if Hero/Juno can steal selective memories, then she could be blocking the Roman forms of the gods from knowing "exactly" who Percy is