Traditionally, speaking of being the best teacher, most of people directly think the person must possess professional knowledge, academy and specialty as well as teach at the school. However, the conservative concept ignores that sometimes parents who raise children are the best teacher as well.
Indeed, the school teachers usually accept the college-trained and professional education to become the experts on their research or specialty fields so that most of people regard the school's teachers as the highly qualified intellectuals. In addition, most of parents believe that the highly educated teachers can teach the knowledge to the children and hope their children can be the highly intellectual one day.
However, the rich insights' school teachers easily overlook each student's behavior and personality which may influence students their own learning like distraction because there are so many students in the class that teachers can't take care or notice each child anytime. For this problem, parents play an important role in the process of children learning. First, the teachers don't understand each child's personality so much as parents do so that parents can find more suitable approach to teach and modify their children's deviation behavior patiently. What's more, parents can teach children anytime and anywhere like informal (accidental) learning and giving kinds of lessons by their lives.
In conclusion, although teachers can teach their professions, without modifying students' deviation behavior in time is in vain. Thus, parents plays a vital role on children's education. That's why I agree that parents are the best teacher.