The end of four years invites a lot of introspection:
People I thought I disliked but realized that the good times with them overall have outweighed the poor memories
Catching up with old friends and now acquaintances (it was interesting! I'm glad to see that we've both grown in different ways, even if that meant apart. You'll always have a special spot in my heart just because of how much we did go through those first 2 years of high school, but in the end, it's been a while haha)
Numbers & Grades: Something stupid, but memorable for me, personally. I struggled a lot in chemistry freshman year and barely pulled off a 90% second semester. I ended this last semester of AP chemistry doing just the minimum with an A+.