What some refer to as a natural narcissism in teens is actually known developmentally as egocentrism. Teens are in fact egocentric by nature; research reflects that this is related to brain development.
The average teen does have the capacity for perspective taking this is not their natural inclination.
As a result your teen may believe that the whole world is watching her at all times. This is why your teen may be embarrassed by something you say or do. It also explains why she may perceive that tiny blemish on her chin as Mt. Rushmore!
Teens also often believe that bad things only happen to other people. This concept known as the 'illusion of invulnerability' helps explain in part why some teens are prone to high risky behaviors.
Finally teens believe that their experience is unique. They believe that no one has ever felt or thought the way they do...especially their parents. This is why your teen may turn off when you say something like: "I know how you feel," or "I felt the same way when I was your age." Your teen doesn't believe you were ever his age!
Instead try telling your story or offering your advice by saying something like: "When I was your age..." or "If I were in the same situation I would..." When you avoid telling him what he is thinking and feeling, he may actually stop and listen to what you have to say.