People claim cigarettes are more psychically addicting, than mentally, but I'd have to disagree.
Though, the longest I've smoked cigarettes was for a 2-3 month period, and this was a few times where I went on a 'cigarette binge' if you want to call it (lol), and I never felt any physical withdraws. Now, I can imagine it that over time, after a few years, that it is probably a lot worse, but honestly, how bad can it be? I'm sure you might get huge headaches the first few days, but I really don't think it can be THAT bad.
I did smoke blunts for about 3-5 years, and it got to the point that I would crave smoking weed in a rello more than the weed itself. I have been told there's no nicotine in just a cigarillo, but as soon as I would take my first hit of the blunt, my headache would go away and I know it wasn't from the weed.
My grandma quit smoking after 40+ years, and he says he still craves one every once in awhile. I think what people crave most is a cigarette being their 'go-to' whenever something happened and they felt like they needed to relieve some stress.
For instance:
1.) mom/girlfriend yells at you, smoke a cigarette
2.) pulled over by the cops, smoke a cigarette
3.) late on bills, smoke a cigarette
With that being said, I think the hardest part about 'quitting smoking' is finding something else to relieve the stress, rather than smoking a cigarette.
I could be wrong, this is all based off speculation and my own experiences. Like I said though, I haven't smoked for a long enough period of time, but I feel like I've smoked long enough to understand why people feel like they can't quit. I have quite a bit of knowledge regarding drug usage, depression, etc so this is just my 2 cents on the subject, and your mind is very powerful and can talk you in or out of something within seconds, but it's all up to the person. Some drugs are physically addicting, but the only drug you can die from withdraws is alcohol, so if you want to stop an addiction, it's usually more mental than anything. Please don't quote me on anything, as this is just a summary of the matter.