Nothing happened, then he felt something, at the edges of his mind creeping inwards, it was like at the train station but more subtle and harder to notice. "Difficult. Very courageous, I see. Not a bad mind either. There's talent, my goodness, yes - and a nice thirst to prove yourself, now that's interesting... So where shall I put you?" The voice was inside his head, it was at this point Harry connected the dots. If the hat gave him the same feeling as the strange man on the platform and the hat was inside his head. That meant the strange man had been inside his head. Oh god Wizards could read minds.