User blog comment:SayuriDarling/The Mark of Athena Official Discussion/@comment-112.134.186.80-20121113170916/@comment-94.168.77.157-20121113190753

First off, a lot has changed sinmce the first series. He lost his memory, then found out his friend-slash-cousin - who lied to him about knowing him when Percy had no memory - had been kidnapped. Also Heroes of Olympus is 3rd person, rotating. Everyone sees everyone else in a different way.

And his new phobia is of suffercating, not drowning or water. True, drowning could count as suffercating, but in SoN he was drowning in mud, not water.