A few weeks ago while checking out at a grocery store, the cashier called me "ma'am". It was like a bullet to the heart, the word ringing in my ears like a slur. Not long after, the same thing happened again, a different grocery store, a different cashier. Some friends attempted to assure me that these incidents were in all likelihood nothing more than good etiquette or a Southern upbringing. I countered that we lived in New York City. Then I swore off grocery shopping for good.