"Well bless your heart"...

Did you ever see/hear a Sensei from Japan or Okinawa look an American in the eye, say "sou desu ne?" and smile?

This is the equivalent of a Southern Belle saying "well bless your heart!" to someone.

For those not from the South, this is the same as saying "boy are you stupid, but you just cannot help being yourself". To put it in polite form.