Going to sleep at 3 AM and waking up at 6 AM to spend a day taking math classes, running a mile in gym, eating lunch at 10:30 in the morning, and watching your gym teacher teach a sex education class and put a condom around her fist to prove that "no man is too big" seemed normal in high school. Then, of course, you grow up and go about your life and suddenly remember that there was a time when you really woke up before the sunrise every day and thought where you sat at lunch was the hierachy of all social situations.
High school was just an escalation on the weirdness of elementary school, though. Remember all the bizarre things that were found in Elementary and middle school public restrooms? Why was there an era in third grade when every kid was throwing up all the time? Did every school have a girl who hissed?