Why do they smoke?

Why do they smoke?

DD1 and I had the following conversation several nights ago...

DD1: Mama, why do people smoke?
Me: I don't know. Maybe they think it's good or cool to do it.
DD1: But isn't smoking bad?
Me: Yes, sweetie, smoking is bad for your health. It will make you sick. Do you want to get sick?
DD1: One time, I saw a kid on the show you were watching (I was watching Mad Men) and she was smoking.
Me: That's not good. (Note to self: Make sure that all of the kids are asleep before watching Mad Men. This is after all a show set in the 60's when sex and smoking cigarettes and Dutch Master cigars seemed as commonplace as eating)
DD1: Do they know it's not good for them?
Me: I think so.
DD1: So why do they still smoke when they know it's not good?
Me: Well, why are you sometimes sneaky when you know it's not good?
DD1: (sheepish grin)
Sometimes, it's easier to throw back the question to them than answer such a deep philosophical question on man's humanity. Hehe.