Mine is people who are stubborn to the point of ridiculosity when the option of vaping is presented to them.
The other night I was at George's in Unionville, CT (great food, great bar if you're ever in the area), and while I was waiting for my take-out lasagna dinner, I saw the usual assortment of wretches huddled outside the door, sucking on their stinkies. Student of human psychology and Good Samaritan that I am, I thought "what the heck", and, Woo-powered EMDCC in hand, approached a late-50's-ish-looking couple whose faces bore the scars of many years of smoking. "Excuse me", I said, "but have you heard of the terrific advances in the field of electronic cigarettes, and what a wonderful alternative they are to smoking cigarettes"? The lady says to me "Oh, someone told me those were bad for you".
God help us all.