Katie changes her backpack from the first day of school. It was a blue small backpack on the first day they entered school. Now throughout she has a black backpack that she brings to school in season 1.
The trivia items below may give away important plot points.
While talking about first kisses, Katie is nervous because it will be in front of an audience. Then Lori tells her not to count it and proceeds to tell Katie that she had a first kiss that didn't count. She tells her that it was tenth grade and his name was "Zack, uh... it started with an M." In Saved by the Bell, the actress who plays Lori played Kelly, who was the girlfriend of Zack Morris.