a know a guy who freaks out if he gets close to second hand smoke (he is a track and field athlete). But as I mentioned, smoking is widely practiced among professional dancers, some of whom have insanely good stamina.
I am one of those people who freak out and hate second-hand smoke. I don't think it is fair that just because smoking doesn't greatly affect some people (we are all different), some smokers think it is OK to expose other people to it, especially around entrances to buildings or while walking on a sidewalk
In my childhood I had asthma. My caregivers were my paternal grandparents who, unfortunately, were not aware of how bad it could be for children. They brought their friends over and chainsmoked in a small apartment without the windows open. When I was 4, even, my grandmother let me take a puff of her cigarette.

My mother also, to this day, smokes, but only about 2 cigarettes a day and thankfully she does it only in a particular washroom, with the window open, and our house is moderately large.
I never had asthma again after I stopped being babysat at my grandparents' apartment. I had spirometry performed just this Monday and my lung function/capacity is excellent--it looked about 15% better than the average person of my age and height, etc.
I am still torn on my attitude towards smokers in general, however, since it must be tempered by compassion as a health professional. I know many who want to quit smoking and try to, but find it extremely difficult to stop. I am bewildered when it comes to talking to patients about it, though, because I cannot rationally justify it. It costs money, damages your health, and ages you prematurely (for those who care about what they look like.) Blahdeeblah, I hear arguments about how many other habits aren't good for your health e.g. fast food, but even fast food has some nutritional benefits. Smoking is also a "hot topic" for me about which I feel passionately about, because here in Canada we still have a mostly public, universal health care system. All the health burdens on individuals caused by smoking costs the whole society, regardless of how much tax dollars are earned from tobacco sales. Cancer drugs are expen$ive, not to mention all the adjunctive care and loss of productivity and life.
Those publicly-funded health advertisements in my elementary school days were successful in "brainwashing" me about how cigarettes, alcohol, and drugs are generally bad. For the last 7-8 years I noticed that there were less of those programs being promoted here in Ontario, but it has picked up again in the past 2-3 years. I think there was a resurgence of the need to do it, as I read some statistics about how the downward smoking trend was rebounding a little.
End of rant and off my soap box. :/