I also agree about the number of years. If it is radical, like Goodwill Hunting, then dual enrollment seems best. The recent Goodwill Hunting type at Hunter stayed in high school for arts and language and did all the math and physics at Columbia at the same time, then went to NYU for the math prodigy program when he would have been an undergrad. So he did his undergrad at Columbia while he did his high school. Wherever thye go to college, there should be a high school that lets them do some courses to "stay in high school". Whether you want prom or not, usually kids like to date in high school.