When you first took your first drag of a cigarette as a teenager, you would have felt good because you fitted in with your friends and peers and you may have felt good as you were being rebellious.
You would have coughed and spluttered because of the horrible poisons entering your body but you persisted because you felt cool to be hanging out with your friends. Basically anything you persist with eventually becomes a habit. And this is why we use hypnosis to talk to the unconscious mind as it is so powerful as it controls our habits, imagination, belief systems and is also there to protect us.
Because you felt so good when you first started smoking, your unconscious mind believes smoking is good for you, yet we all know it will make us sick or even kill us. We need to get your unconscious mind in agreeance with your conscious mind which knows smoking is bad for us so it is easy to quit cigarettes.