I guess I should face life as it happens and not worry about it ahead of time ..
I cant tell you how many parents I've spoken to who could not accept this and instead lost out on so many aspects of their kids teenage years. This is an amazing part of their life where they're getting to the point that they can start exploring their world in a new way.
The best thing I can say is to encourage them to try new things and explore new ideas, within reason. Dont let them do anything that would actively hurt them (drugs, dangerous behavior, etc) but certainly encourage them to try something new that they're interested in (a new sport, local traveling, researching different cultures and beliefs). Their journey can be just as much fun for you as it can be for them!