The Defence:
Smoking is cool.
The harder the establishment tries to tell me it's not, the cooler it becomes.
I like smoking.
Much as with masturbation in days gone by, no amount of preaching is going to make me stop liking it.
The Courtesy:
Please don't assume I'm a rude puffing bitch.
At least wait for me not to have asked whether you mind me smoking (which will happen, but only very rarely) before going off on a diatribe about how inconsiderate all smokers are.
Please don't lecture me about what a disgusting habit smoking is.
It is not considered acceptable for me to remark on your BO, or on the fact that the slurping noises you make with your pint are making me gag. The fact we have a difference of personal habits does not mean you can call me smelly or flegmy.
Please don't elaborate on the health risks smoking is exposing me to.
I'm sure that in the confines of your home you do all sorts of things which are bad for you. I don't stick my nose in your medical history, and you can kindly stay out of mine.
All of the above are plain good manners, which isn't I think too much to ask. One's politeness, personal hygene and state of health are not considered by society at large to be suitable subjects of discussion, except by mutual consent between close friends. It strikes me that smoking and smokers are somehow removed from that simple equation and left to dangle perilously in the wind where anyone can take a potshot at them. I'm not here for your amusement. I smoke with my own lungs in my own time, and save for politely asking me not to do it in your face, you can kindly shut up about it.
Just in case this is worth mentioning, the "you" in the above is strictly hypothetical, is not geared towards any one noder or other person, and is definitely what it claims to be - a list of general guidelines, not an acrimonious whinge.