As another anecdote:

I started college at 15 while being dual-enrolled both at a high school and college 2 years ago. Unlike anonymoushn's experience, I went to a commuter community college, so I didn't live on campus or really participate in any campus events, as sparse as they were.

I do feel that I've missed the high school and college experience to a degree, since I've spent my last two years at high school attending classes with older people of relatively mediocre talent with little interaction with others. I lost touch with most of my friends from high school that I kept up with since middle school, since we really only saw each other in school.

I will echo anonymoushn's experience that it was a pretty stressful time for me, being pretty isolated and alone and forced to do a lot of things alone. There were some periods where I got the lowest I have ever have into the pits and depths of depression, mainly from being so alone and feeling a little hopeless. It didn't help that I was working insane hours during my only free time during the summer between my junior and senior years of high school and had no time for any fun or relaxation at all.

I do appreciate the fact that I had 2 years of college paid for by the state fully, and that I got a leg up in life that way. I also spent a lot of that 2 years listening to a lot of music and learning a lot about myself. There was definitely a lot of wasted time and things I regret from that period. I almost failed out my first semester at the community college from procrastinating so much and being thrown into such a new and strange environment with no support. My academic record went on a big nose-dive during this period and I really regret that, it hasn't helped me any during my college admission period.

It was pretty bittersweet, and I feel the effect that it has had on my life since I'll have to continue at the same college for another year to finish an associates degree in computer science (another downside to starting college alone with no support and as the first in your family to go to college -- a lot of __really__ important things like planning out your classes and academic roadmap don't really occur to you until it's a little late), and have little choice but to attend another cheap state commuter college for the last 2 years of the Bachelor degree.

Another upside is that I was exposed to the concept of taking responsibility for my own personal growth and development mentally, physically, and emotionally/socially in my own hands. I realized around the 3rd semester of my time here, I got into panic mode realizing I had 1 semester left of high school. I felt like it went much too fast and that I missed too much, but refused to just wallow in despair like before. I've gone ahead and taken the initiative to try to learn about things that interest me and skills that I both enjoy and can market, take care of my body by learning how to eat better, exercise regularly, sleep on a sane schedule (a problem that slaughtered my productivity and academic record), and to be more bold and confident amongst groups of people, especially to girls.

It's been a bitter pill to take, but I think I've grown a lot as well.