Like Hal, smoking helps me to relax and keep my sanity. Like everything else in life that can kill you (i.e. alcohol, cigarettes, cigars, good food, etc.), the key is moderation. I smoke Marlboro Light menthols, and a pack lasts me about 3 days, which I think is pretty darn good, when comparing myself to the likes of my wife, who only started smoking a few months before I did, and she smokes Newport 100s. She goes through 2 packs a day, now. I try to minimize my smoking, limiting myself to about 4-6 cigarettes a day, since anything more will be going to waste(not giving me a buzz) and will most likely give me a headache, especially if I don't eat anything. When I see my wife light up in the car on the way to a restaurant, light up while waiting to order/waiting on order, light up after the meal, and then light up again on the drive home, it nauseates me. I don't know how anybody can smoke that much. Also, I undergo physical training on a daily basis that tends to involve a lot of cardiovascular activity, so my breathing is in pretty good condition.