"Drinking, it seems as if it's becoming increasingly common among teenagers"
Historically, hasn't drinking always been common among teenagers and even children?
You say kids/teens smoke and drink because it's a mature adult thing to do. WTF? It gets you intoxicated, that's why most people do them, I assume. I've never even considered the idea that it was a mature or adult thing to do, I just thought "hey this feels good".