Being a 15 year old JavaScript hack isn't necessarily a bad thing. If the Internet craze has taught us anything, it's that a age, gender, race and creed truly mean nothing (at least, I hope we've learned this). Never before has the world been so open to skilled youth with a thirst for knowledge and success to get a good share of both. The trick is simple and really involves just one key element - at all costs, avoid stagnancy.
Stagnancy is a very common and very simple trap, especially for kids in rural or suburban areas where they don't have much competition at any level to achieve technologically. In my town of three thousand, there are a handful of tech inclined kids, some of whom I've hired to try and help grow (and because they make great employees!) And among adults, those with skills all work in IT for the local companies. As far as Internet development goes, there is zilch, especially back in '94 when I expanded my father's communications consulting firm into the digital market (from print and video it was logical), and our only viable competition was the ever popular niece or nephew, the 15 year old JavaScript hack.
I was 15 at the time. What made me different? I was brought up in the family business, and understood more than HTML and FTP. 70% of work in this business is NOT design. My Internet knowledge merged with the processes and work ethic my father had developed in the previous five years of the business, and that made all the difference. Starting with our first Internet project, our focus was always on perfection in the client's eyes, quality work and quality support. I've never stopped learning - new technologies, new procedures, new services.
So my point is this: don't let yourself think you're professional, let your work speak for you. Some stories float around about millionaires who never went to college. Try that if you like, but don't ever ignore the whole package in this business. Learn how to work with a client, learn how to push yourself at any level of adeptness, never think in terms of good enough. Never let success go to your head. And never, ever design crap - digital graphic design is every bit as demanding as it is for print and more so, and requires study, practice, time and passion.
If I can give a 15 year old JavaScript hack one piece of hard advice, it's be this: review everything you do, even if it's just for yourself (like your homepage of your quake 3 clan page or whatever) once a month with a pen and a pad of paper in light of what new things you've learned or what new concepts you've considered, keep all your notes, and review them for changes. Watching yourself grow in skill and knowledge will allow you to keep perspective, help you see what more you should do, and motivate you to be better.