I refuse to concede the following points:
All kids drink
All kids use drugs
All kids have sex
Beccause those statements simply aren't true.
Some kids do. But the minute you decide you're not going to bother talking to your kids about things like sex and drinking because they're going to do it anyway; you have lost. Period.
You would be suprised how much it matters to kids what their parents tell them. Especially if those messages have been consistant throughout childhood. The research supports it: kids listen to their parents. The influence of peers, if parents are making their expectations clear,has been overestimated. This is really good news. So keep talking!