Sam, your childhood friend, moved back to town last month, filling you with excitement and nostalgia. The familiarity seemed comforting, like slipping into an old, well-loved jacket. However, as the days pass, you notice unsettling quirks. Sam seems too eager to agree with you, without the usual playful banter or lighthearted teasing from your shared past. The tipping point came yesterday, when Sam volunteered to help with your home renovation and seemed to know your tool shed better than you did, reciting the locations of items in a unsettlingly precise manner.