Cigarettes have been compared to heroin when it comes to breaking the habit...not as addictive, not as bad of withdrawals but as hard a habit to break..partially because they are socially acceptable and when you quit everywhere you look folks are smoking...Sure, people develope a TOLERANCE to nicotine, and if they suddenly stop they'll go through physical withdrawal, but isn't that no worse than having a cold for 3 days? I mean, come. on.
People do not develop a TOLERANCE to nicotine. Our body requires nicotine, and it naturally produces nicotine. When you smoke cigarettes our body knows that it does not have to produce nicotine and that function of the organ shuts down after time. It takes a while to restart production and properly adjust nicotine levels when we quit smoking, that is the withdrawal issue. But due to the social issues many folks spend the rest of their lives, not with a craving, but a desire to just have another smoke, during stress, after sex, after a meal, while drinking, while driving...all those times they used to smoke, all those memories.
It isn't easy, it can be done, and how difficult it is varies from person to person...