Quitting smoking is hard for many reasons, here's just one!
Nicotine dependence - Like heroin, nicotine is one of the most addictive drugs in the world. The nicotine in tobacco causes dependence by going to the brain quickly (within six seconds) and by, at first, giving a feeling of alertness and increased performance.
Generally, people fail to remember the toxic signs of smoking they had when they first smoked: the dizziness and nausea. Eventually the dizziness and nauseas goes away and is replaced by physical tolerance. This means that the smoker needs more and more cigarettes to feel the same effects.
