Why is quitting so difficult?
Nicotine is addictive: Nicotine, the main addictive chemical in cigarettes, is part of the reason why quitting is so difficult. This chemical affects the A chemical released by the brain that plays a number of roles including motivating behavior, pleasure, rewards, etc. in your brain, and as your body gets used to the level of nicotine, you become dependent on it. As your nicotine levels drop in between cigarettes, your body begins to crave the chemical, which makes you feel the urge to smoke.