While Hermione was no stranger to physical contact, that was usually between close friends, and so she was surprised when he actually moved to give her hair a ruffle. It made an embarrassed sort of blush begin to rise to her face, an instinctive response to the possibility that she was being regarded as a child, even if she wasn't entirely sure that that was the case here.

"Th- thank you," she replied, managing not to sound too flustered. "I appreciate the, um-... the distraction, but I suppose we can talk more some other time?" Preferably during a time when she was better suited to believe him when he claimed to be the sort-of ghost of a famous historical figure.