"I'm fairly certain that they didn't actually light the cig for me, nor did they put it in my mouth or anything else."
But they did. They paid and sponsored programs to show smoking happy people, you couple in love, or "heroes" all lighting cigarettes. Never sponsored a program showing you a 50-70 guy dying horribly of cancer. They influenced the culture to to make people smoke more and more, all the while knowing they were sending death sentences down the line. WITHOUT that cultural influence,a dvertising, and glorification in the media of the cigarettes until recentely, I can wager that you would not have lighted a cigarette. In fact now that smoking stopped being cool, cigarette smoking in high school has dropped like a stone in the last 40-50 years. 50% of youth smoked by the end of high school post war (50ies), nowadays it is less than 20%.
Your smoking was not your decision alone, but also a product of a culture of praising smoking in media.