User blog:Cameron Chappell/Percy recognizing Leo

I might be confused but how was Percy able to recognize Sammy as Leo in the pic in Alaska and in the video scroll. He was missing when Leo, Piper, and Jason made it to Camp-Halfblood. He also recognized the Prophecy but not there when it was spoken at Camp-Halfblood. I love the books but I think he might he might have taken on to many projects, and if he starts a Norse Mythology series I would wait and finish the one's he's  doing now then do that.