Unless you have been living in a cave and cutoff from civilization all of your life, you should already be aware that smoking is bad for your health. Your health is the one most important part of your life that you should treasure and respect . Maybe you do smoke because you do not respect yourself. Smoking is additive and it has been found that a young teenager that wants to experiment with smoking will be addicted to smoking and will have withdrawl symptoms after only three days.
Many people start smoking because of peer pressure.
It has been proven over and over that smoking causes cancer. Many people can think of at least two people in their families that have died of cancer due to smoking. Smoking is also very addictive because of the nicotine that comes in the cigarettes. By personal observation, I have noticed that people that have smoked have lost their youthful appearance at a younger age. I have seen people that are younger than me that are smokers who have wrinkled skin and look much older than me.