Imagine walking in on a flight where the cabin is filled with cigarette smoke, just like the smoking lounge of the airport, and you have to sit there inhaling all the smoke if you want to air travel. Can’t do it? Well, You had no choice in that till very recently.
Though the US banned smoking in domestic flights by 1988 due to the health concerns. A global ban on international flights only came at the start of the 21st century. Before then, a passenger would be asked if they preferred a smoking seat, which would usually be at the back of an aircraft. It is also the reason the airplane lavatories still have an ashtray.