I see the cannabis thread has turned into a confessional 😁
In my experience, cigarettes are much more than a habit. Some experts have reported quitting is harder than getting off heroine. I wouldn't know about that, but I experienced both physical and mental pain from withdrawal by day 3, that was so intense I cried out to God for help. I started smoking at age 16, because it was the cool thing to do at the time. You know what they say, young and dumb.
I agree with Lareli, caffeine is also addictive, having experienced the headaches, mental fog and general feelings of overall physical pain, when I can't start the day with my favorite cup a Joe. I love it so much I once wrote a poem about it. I try not to think of a time it may not be available, I'll face that demon if necessary I'm sure.
I was 20 before I smoked pot. I grew up in a generation gone wild. Sex, drugs and rock-n-roll, It was the true age of stoners, everything from pot, LSD, mushrooms, cough syrup with codeine, airplane glue, and huffing paint thinner. Not a pretty sight to see so many out of control and wasted people, didn't make me want to participate.
I did finally succumb to smoking some pot though and like Pamela, it made me paranoid, so much so I begged my friends to take me to the hospital. There was a saying at the time, "better to be dead than square ", not me, I was happier being square. Besides, I still had my coffee and cigs. Now it's just coffee.