I smoke about 2 packs a day. I haven't quit because I enjoy it. I could get rolled on by an out of control 18 wheeler, I could lose a tire and flip multiple times, or the car in front of me could slam on his brakes, and I get crushed between two cars, and that's just on the way to class.
Any of us could die at any moment for any reason, and a top killer is stress and the complications it causes. These fleeting moments of life are all we have, these moments that we will never have a chance to live again. I want to spend mine living the way I want, and I choose to live as a smoker. Stupid as it may sound, it's my choice.
I may quit in favor of a healthier lifestyle, now that I'm working out more (and enjoying it a ton), but I'm not pressuring myself. At the moment, I enjoy it.