On Leisure : Gas Chamber

I was eating at IKEA with my girlfriend, can't help noticing something. Nope! Of course not pretty girls la. My girlfriend will poke me in the eyes! We were sitting right infront of a chamber. She called it "smoking room", I called it "gas chamber". Men, women, boys and girls were inside inhaling oxygen... err, wait, sorry, it's "smoke". I was wondering whether they realised, their lungs are slowly but surely deteriorating. If they realised, how come there's no stop to this? Does anyone out there successfully quit smoking? If yes, how?