I'm curious, what did you write about? Fiction/non-fiction? Still writing or just hacking?
Putting a book together at that age is a respectable achievement.
I still write, though I haven't written anything as ambitiously. My start-up is one that focuses on creative writers who want to learn to write at a more professional level, so it lets me get away with doing both. And I'll probably be writing something for NaNoWriMo in November: if I like that, I'll spend a little bit revising and seeing if any publishers are interested.
The two things go nicely together, because with literature you get used to putting things together haphazardly until they work: hacking gives you a more utilitarian approach to doing things. I find that when I'm in the middle of programming, I write better - if that makes any sense to you.