The use of "but" question made me think of an odd speech pattern I frequently encounter in the Southern Tier of western New York. In answer to a statement such as "I like chocolate", the standard response is "So don't I", when they actually mean "So do I". It's very prevalent, and highly irritating. I'm finding it in cross-generational usage, and at varying levels of education and sophistication. I've lived in many other places, and have never encountered this structure before. Has anyone else experienced this?