Every trouble in a child's life is the result of something. Sometimes, simple unawareness in the childish psychology could cause many uncured psychological complexes and troubles. Every children psychologist suggests that it is better to prevent than to cure.
Discipline
The first thing every child is to learn in order to live harmonious and sound life is discipline. Discipline means a lot, if you want your child to be healthy and well-organized. It concerns many routine affairs like brushing teeth, going to bed, eating breakfast, learning the lessons, playing with the friends and so on. So, let's try to understand what does discipline start from? When a child is a very small, you define the time of every activity by yourself. Later you try to check the proper time for every activity as well. But at the same time your will could be opposite to your child's desires. Children who stick to the everyday schedule could easily understand your explanation that it is not worthy splitting off the schedule in order to read a book late in the night as it could be very hard to wake up in the morning. But if your child is too stubborn and capricious, it is better arranging the schedule step by step. One day it is better to devote some time to the eating habits, another time is appropriate for managing bedtime.
At school a child is taught to be disciplined as well. Ask him what his school matters like, what's new and unknown he/she learns and how he/she copes with the new life conditions. A conversation with a teacher could be helpful as well. Common work of the teachers and parents is to be positive in the building the most comfortable schedule of a child.