Grr people, stop with the "but you could get hit by a bus " argument -_- It's extremely difficult if not impossible to prevent things such as being hit by a bus or car, being in an accident/crash, etc. (except if you never left the house). Smoking is preventable and if you don't smoke you've almost entirely cut out the risk of contracting a smoking related illness/disease (I say almost because there's still the minute possibility of catching one through passive smoking).
I'm not going to call you all stupid for smoking because that's absolutely rediculous, I know plenty of people who smoke who are incredibly intelligent people, but it IS a stupid thing to do and I'm those of you who do smoke know why it's stupid.