There are tons of movies and books about the horribly stressful, awkward, and crushing experience that is high school.
Now where do you think all of these authors would come up with that idea? Is there a decades-long conspiracy of writers and artists who have decided to perpetuate this notion? Is there a secret pact a bunch of people have had who've decided to portray high school in an awful light on purpose as part of a grand scheme to give your formative years a bad rap for no reason whatsoever? That could be one theory.
Or the more logical and obvious and relatable one is that yes, high school is absolutely terrible for most people.