It illustrates the third principle of Developmental Psychopathology which is, "Life may be better or worse in adulthood".
There are children who suffers from serious disabilities that becomes more disabling when they get older. However, there are some who become happy and productive when they reach adulthood. Just like Gerald, who happens to have attention deficit hyperactivity disorder (ADHD), he has difficulties in learning when he is younger. But he focused on his strength which is arts. This lead him to be a successful artist as an adult.