Can you choose all your classes in high school? I'm not familiar with the american educational system.
In Norway, you have to finish "Videregående" (Advanced) School before going to the uni. You can choose a couple of classes, but most are predefined, depending on which program you choose. (Pre-Uni, Drama, Artisan, Nursery etc.)
Not sure for all high schools, but most you have a few normally around 3 or 4 you have to have each year, and a few you need to have within your four years, but other than that it is up to you. Like i was required a language class, a science, and a math, i got to choose my other, but since i knew i needed 1 physical education to graduate i took one for my freshman year.