Coalescing developments in brain, mind, and body bring about qualitative changes in all aspects of the teenager’s life, with both great advantages and challenges. Being able to imagine how things could be, and seeing multiple possibilities, can lead to idealism or cynicism. Teens are aware of the complexity of thought and feeling and know that neither they nor others are always aware of motives. Along with a profound sense of uniqueness, they have the capacity to connect with others in a deeper, more intimate way and to be involved in a complex network of relationships. At the same time, they can feel alone in dealing with emotions at a new level of complexity. To thrive during this period they must be able to tolerate a level of vulnerability never before experienced, because they know others may be thinking about them and seeing beneath the surface of their behavior, just as they can.