I think part of it is also the big fish, little pond --> little fish, big pond phenomenon. When high school teaches you to define yourself as intelligent, academic, and driven and then you're placed in an environment where everyone else has developed a similar set of character traits and amassed a similar collection of academic achievements, I think students suffer a bit of an identity crisis. All of the sudden very key components of one's character are the norm, and the transition is far from easy.