Often when younger children have no one to play with when they are left behind as the school year begins, they are eager to go to school and be a part of what the others are doing. This is true of Scout.
In Chapter 2 of To Kill a Mockingbird, Scout recalls how she often spent hours in the tree house, looking over at the schoolyard through a telescope, "secretly sharing their misfortunes and minor victories." Unfortunately for Scout, her first day does not meet her expectations of school. Before the morning is over, Scout is brought to the front of the classroom and her teacher, Miss Caroline, hits the palm of her hand with a ruler before placing Scout in the corner. Further, Miss Caroline criticizes Atticus for having taught her to read improperly.
Like many precocious children, Scout is well-meaning, but when she tries to help her teacher, who is new to southern Alabama, by offering background knowledge on some of the children, Miss Caroline misreads Scout's intentions. She thinks that Scout is trying to undermine her authority, and she disciplines the girl. Thus, Scout ends the day miserable.