I once read somewhere that each cigarette you smoke can shorten your life expectancy by as much as seven minutes. I'm 30 now and I've been a pack-a-day smoker for roughly eight years. You do the math. . . . I've got more pressing matters to attend to. Like taking an elevator down to the ground floor of this office building, pacing and puffing with the other nicotine-addicted employees here who've been banished to the street, and pondering the questions: "Why do I smoke?" and "Why don't I stop?"