He spins in place, arms out as he's swept up by some wild thought or another of his. He seems to be quite happy simply talking to himself about how smart his current plan is, and what an intelligent man he is. He doesn't notice the approach of someone else until he literally turns toward them, eyes widening as he realizes he's been rambling on about what might seem like nonsense to the casual onlooker.

Any shame he might feel quickly evaporates, though. "You! Why have you come?"