Okay, so answering this had to wait until I had gotten some sleep and coffee (Way to make me think way too much! :P ♥)

I don't think he is hiding something, well aside from the dork part, but that can definitely be explained by the age. And he isn't so much trying to make himself be something he isn't. It is all him, he is just pushing the part he is embarrassed about down until the appropriate times. The dork comes out (Mr. I got an A+ on my second day of school ... back when I still sent them to school...) and it will pop up a time or two in the story as well. Already has actually, in subtle ways. It is more like he is choosing not to define himself by that characteristic.

Of course the ones he is choosing to define himself by are ... questionable? Yeah, let's go with questionable (because it sounds better than "really fucked up").

You should totally feel free to smack him upside the head though! I can't be the only one that wants to do that all the time!