I often think that its not fully appreciated how powerful nicotine is to so drastically pervade and corrupt many aspects of ones thought patterns, but in a way which bypasses full conscious inspection. This really becomes apparent once one is unchained from nicotine in all its forms, with the good old cigarette being the most pernicious of the modes of delivery. The hit is pretty crap when one is not addicted; it lacks the bells and whistles that come with the other drugs which rival it in it's ability to hook the user, and yet its claws run deep. Once well entrenched in the habit, the hit matures as the relief from withdrawal it offers becomes more worthy. For me, nicotine exceeds opiates in terms of addiction potential.
For those seeking freedom from nicotine I had excellent results with a compound called Cytisine , branded as Tabex, which allowed me to quit cigarettes and NRT and, more importantly, has allowed me to get to the point where I have no cravings since completing the 25 day course, and I am respectfully conscious of what a powerful agent nicotine is. Varenicline aka Chantix is a derivative of cytisine; pretty remarkable stuff IMO.