One of the reasons outstanding children fail when moving to the professional career is the change of criteria. While you are a child you a judged on a different terms than adults.
Children are judged on technical aspects of the job: how well you can reproduce a piece of art, or how technically precise you are. Adults are judged on how well they can interpret a piece of art, how well they convey their emotions.
This idea is related to Peter principle (every employee tends to rise to his level of incompetence)