My High School and Middle School were the same building, with most of the same people, so the experiences kind of blended together.
Middle School and 9th grade were easily the worst parts of my life. I was constantly bullied and nobody could or would do a thing about it. I could tell them exactly how, when, and where it was happening, and they couldn't do a thing about it because it wasn't obvious. Really, I look back at then and hate myself for being an easy target.
10th grade was okay since all the bullying stopped, but I had basically no social skills, and few friends.
11th and 12 grade were great. I had joined the school's bowling team in 9th grade and stayed in the program all four years. In 11th grade, I was one of the three best bowlers on the team, I had more friends, and got rid of a little of my extreme social awkwardness. I helped take my team to the state finals twice, getting 12th and 4th place in the 3rd and 4th years of our program's existence. I went from easily bullied wimp to semi-respected accomplished varsity athlete.
Academically, I was never challenged by my school. I ended up 5th in my class with no effort, was invited to National Honor Society twice and kept a 3.8 GPA. I ended up refusing to join National Honor Society twice because I thought the idea of it was dumb.
I really hated when people said high school is the best time of your life. To me, that just sounded like "It's all downhill from here", and that's just depressing.