User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-3146930-20130203215241

So one thing I've noticed a lot is how everyone is commenting about how Percy is different from how he is in the Percy Jackson and the Olympians series, and I have a few thoughts:
 * First off, The Heroes of Olympus is told from a third person point of view. While some of you might be saying "That's obvious," there is more to it. In our own minds, we sometimes play-up what we see, hear, and think. So for example, Percy may think he's funnier than he is or think he is stronger, and because we know what is going on in his head during the PJO series, but in the HoO series, we see him in a way that other people see him and we aren't always in his head. I mean in a way Piper put it best, as Percy is built up to be this huge hero in PJO, but she points out how she expected him to be more impressive based on those stories.
 * And the second, maybe less obvious reason, is that Percy is at a time in his life where he is growing up. For a lot of us, 12-16 years old is a time where people start telling us that we need to pick what we want to do with our future and it can be scary. As shown in The Demigod Files, Percy's greatest fear is the Great Prophecy, meaning in a way he is scared of the future. However, when the time for the prophecy to happen does happen, he faces his fear and manages to actually look to the future. During the HoO, Percy is now looking to the future instead of hiding from it. He is thinking about a family and a family for his children some day. It is actually pretty impressive honestly.