I didn't find this out until I had already graduated, but my school district had a self-paced high school where you could take classes at your own pace. It was

I didn't find this out until I had already graduated, but my school district had a self-paced high school where you could take classes at your own pace. It was meant for disadvantaged kids who could not, for various reason, be in-class for 8 hours a day, 5 days a week. However, another reason you could go is if you wanted to graduate early. My wife finished her high school degree just a few months after her 17th birthday; 2 years of "school" were completed in 3 months. Had I gone a similar route, I could have been done with a doctorate degree by 23 instead of just finishing undergrad.