At the beginning of the story, Laurie's mother mentions that the day her son attended his first day of kindergarten was the day he changed from being her sweet-voiced tot to a confident, swaggering little boy. As Laurie's mother sends her son off to school, he renounces his corduroy overalls with bibs in favor of wearing blue jeans with a belt.
In addition to his appearance and clothing, Laurie's character also changes. As he heads to school with the older neighbor girl, Laurie forgets to turn around at the corner and wave goodbye to his mother.
Laurie's mother also mentions that he came home the same way, by slamming open the front door and raising his voice. During dinner, Laurie speaks insolently to his father, takes a cookie without permission, and excuses himself from the table. As the story progresses, Laurie becomes increasingly disrespectful to his parents and refuses to comply with their rules.
Overall, Laurie changes into an independent, confident little boy who behaves disrespectfully and acts arrogantly once he starts kindergarten, which is a dramatic change from his former sweet-voiced, innocent personality.