Both my parents, or rather, all my parents - my mother, my father and my stepmother - they all smoked. As a result, I was left wheezing in the wind when I was diagnosed with severe allergies at age 8. Allergic to basically everything I breathed. (Thank you, parental units.)
My parents didn't provide any treatment for me. It wasn't until I was out on my own and having serious trouble breathing at certain times of the year that I finally started getting allergy shots. They helped immensely; I don't take them now, though my allergist thinks I should. Well, some day, when I have the money... (shots aren't covered).
I've never had the desire to smoke, and to this day, I get wheezy when downwind of a smoker. And, having lived without in-house smokers for over 20 years, the foul smell of stale, lingering cigarette smoke about a person hits me with a wallop. I've never had any desire to try that weed nor any other as a consequence.
My father quit smoking when he was 70 years old. He's suffered numerous lung infections because of smoking for nearly 60 years, and now is "short of air" as he puts it.
There is nothing glamorous or cool about smoking cigarettes. Aside from causing cancer (I know the tobacco companies say it doesn't, but....) and contributing to heart disease and stroke, it turns your teeth yellow, makes your breath smell bad, ruins your sense of taste and smell and has a deletorious effect on the health of the people who are forced to live with you in your environment.
In answer to Jalu's question, it acts as both a stimulant and as a tranquilliser. That's why smokers have such a hard time quitting; there's a pyschological addiction as well as a physical one.