"The cigarette should not be construed as a product but a package. The product is nicotine. . . Think of a puff of smoke as the vehicle of nicotine."
-- Early 1970s Philip Morris memo
The most addictive...
It's shocking to me how little is known about nicotine given the level to which it is ingraned in our culture. It's been proven time and again to be harder to quit than anything, including heroin.
The strange thing about nicotine is that it's a stimulant and a relaxant, and the combined physical properties seem to have a very specific effect on mental and emotional states. In regular users, nicotine doesn't bring about any sort of a high, but rather seems to give the user the sense that things are under their control. It doesn't deaden or amplify emotions as other drugs do, but rather brings them into a managable state.
This is what I hear, and what I've gotten through research. I've never been a smoker. I've smoked some cigars, a few pipes, and a couple hookahs (a fine treat), but I've never picked up cigarettes. I think it's for the best. I don't want cancer if I can help it.
But I have to say, getting high on nicotine can be fun. There are quite a few resteraunts (middle-eastern joints) that offer Hookah (or Sheesha) with their eidbles. It's a great thing over dinner: fine tasting flavored tobacco and good wine. It makes for a bit of a floating sensation, and if you get on the bus, if you get the drug working for you, it feels a bit like ice skating right after the zamboni has done it's thing. I understand why some writers can really cut loose after a smoke.
My dad had prostate cancer and my uncle recently passed from lung cancer, so I have plenty of reasons not to pick it up. It really does seem to be a very addictive substance, and I'd advise people not to use it regularly. Just for the sake of their own chemical liberty, if not their health.