At the grocery store, an employee came up to me smiling and said, "you shop here a lot." This has never happened before; I had no idea how to react.

I mean, I do go to the same store on fairly regular schedule, but I didn't know why he would notice. I literally had no idea what to say and basically just stood there and he continued to smile and walk away. I don't really mind; he seemed friendly. It just seems so unusual.