There are so many people who have been addicted to smoking. Although there are many of those who have been addicted to  smoke wanted to stop, but they still end up failure in their quest to stop..

According to some study cigarette  contains differently types of chemical substances which made cigarette addicting. “[N]on-nicotinic components have a role in tobacco dependence and…some tobacco products have higher abuse liability, irrespective of nicotine levels,” http://www.medicaldaily.com/why-smoking-addictive-its-probably-not-just-nicotine-despite-what-weve-been-told-years-260839. The presence of nicotine in the cigarette smoke makes it hard for the smoker to stop smoking. 

In an article I have read, I found out that nicotine, if taken in small amount, can act as stumulant, http://www.quitsmokingsupport.com/whatsinit.htm. Thus,  making it love and more  addicting to the user. The nicotine and other  chemical which are found in the cigarette smoke are the main reasons why it is hard for the user to stop it.