Apollo likes to be rubbed around his face. Especially when shedding. He'll push his face against my fingers as I rub.
I too believe that beardie's can read your mood. Trust is a big issue as well. Apollo get a little defensive when it comes to strangers petting him.
I think they like be touched. If they didn't, they'd scoot away in protest. If they just tolerate it....tough...too bad....petting him makes me happy.