One of the most memorable things I heard about teenagers is that when children grow into that time of their life, they define themselves through separation -by rebellion. The basic underpinning idea is that we are much more attached and dependent on our parents when we are younger, but when we reach an age that we decide we want to be separate, we push back against the authority, pushing them away so that we can create the space to define ourselves.
That idea really resonated with me, and it still does.
It's the "terrible two's" all over again. When a kid turns about two years old, their favorite word is often "no." Disagreeing or denying is the msot important part of saying that "I" am not the same as "you." It is the mark of self-awareness. The mere action of saying "no" is asserting myself. The solution, for savvy parents, is to give options instead of orders (Would you like outfit #1 or outfit #2? Would you like to go to bed right now or in 10 minutes?). Instead of forcing one way, to allow two (maybe three) choices gives such a young child a dregree of independence, self-determination. My choice means that I am an individual, that I get to assert myself, my needs, wants, desires, hopes and expectations.
But then what's so complicated about being a teenager?
As teenagers having a choice isn't enough, because that is still being burdened by a system, by a way of thinking and a host of assumptions about who we are. The mentality is one of: "Forget the choices, I want to determine my own choices! And then I want to pick the one I want from among them!"
We have to determine who we are and how we get to be that person, we want to feel our own influence at that point. The way it works, though, is that we feel a need to "push back" many of those influences, especially those that give orders or determine aspects of our lives... by pushing back we create the space and then get to explore who we are, what we like to do and what we don't. We can't find it if we feel trapped in doing only what is prescribed (this is where peer-pressure and non-conformity also comes in).
For parents the art is one of creating the space without losing basic boundaries, rules and principles. To throw away all rules is to completely lose the anchor for our values and beliefs. As parents, I think it would be really scary to think a teenage son/daughter may lose the values we tried to instill in them. As a teen, it may seem necessary to create the space and explore.
Which is, generally, the basic conflict. It's often less about the exact time of curfew, or specific clothing choice and more about asserting one's own taste or individuality. Perhaps requiring first that we push, and try to expand or move the boundaries further to allow for that exploration.
For a parent, it marks (the beginning of) a huge shift from a "caretaker/manager/teacher role" to a "support role." Truth be told, I think that shift begins much earlier, but it tends to hit much harder at this particular juncture because of the way that the family undergoes restructuring at this point in time (with pushing-away of authority and boundary-moving creating an entirely different dynamic that is foreign to parents' experiences and expectations with their children thus far).