Why do people still smoke?

I was watching the episode of King of the Hill when Hank catches his son Bobby smoking a cigarette, and after Hank begins smoking again who family is hooked and has to go through the hardships of quitting. It's a good episode, but it got me thinking. Why do people still smoke?

There was a time when we didn't know smoking was bad, and those people have no need to feel bad. It was a different time. But it is the 21st century and we still have people smoking. Now I know. It is additive and hard to break so many want to but just cant shake the cravings. But how did they get there in the first place. Now some got pressured in by friends, which is sad to know your friends are trying to kill you, but why does that happen? Why do people despite the facts smoke? It causes lung cancer, heart disease, and much more that I probably don't know about. Cigarette contain arsenic, nickel, and other substances that are must plane out nasty for the body. So again why do people still smoke?

Is it really cool? Because then if so is suicide cool? Granted some people still live long lives whiles smoking, but not everyone is so lucky, nor do I think people who smoke at the age of 85 feel very well, and it aint just because of the age.

What ever it is I still find myself scratching my head wondering why is this still a problem?