I got the same impression. For 15, he's got a pretty level head on his shoulders. If he worked in the same place I do, I have a feeling I'd never have known his age, if he talks and expresses himself as well in person (which it seems he probably does). One guy I worked with was like that. I talked to him for 6 months about a multitude of topics (from games to politics to world events, etc) and assumed he was close to my age (somewhere in his early to mid-20s). The guy was barely 18!