"I accepted the certainty of my untimely death with gallows humor and a calculator. I'd read somewhere that each cigarette you smoke knocks seven minutes off your time on the planet. To amuse myself, I did the math: 153,000 cigarettes = two years of my life, up in smoke." Julia Hansen first lit up at nineteen. Twenty years later, she was editing books about health -- and smoking a pack or two a day. She denied her son fast food, but...