For my part, it has always killed me that schools don't do as one system which I once briefly attended did --- divide courses between academic and social --- academic classes are attended at one's ability level, while social classes are at one's age level.

I was in 4th grade, but attended 8th grade math, science, English, and history (there was a 4 grade cap until after 8th grade classes) while my homeroom, Phys. ed., and social studies were with my 4th grade age peers.

Some teachers at the school were also accredited as faculty at a nearby college, and for students who were able to take courses which weren't able to be taught, either a professor from the college would come to the school to be taught, or arrangements would be made to bus students to the college.

It wasn't uncommon for students to be awarded a college diploma along with their high school diploma at graduation and there were multiple instances of multiple majors being completed.