People understand that smoking affects their health. But there are still a lot of people who isn't ready to stop smoking though. They smoke for the nicotine, but die from the smoke. Some of them started smoking when they were teens. And there are plenty reasons why people start doing it. For example, they try to get rid of stress or they are just bored or their friends or members of their family smoke. But they don't know or they just don't want to know about consequences of smoking. As for me, I am against smoking because I care about my health and I have the will and I also do some sports!