I am Bradley M. Kuhn.
My general interest in Wikipedia (and Wikibooks, by extension) comes from, as Jimmy Wales puts it, inspiration from the Software Freedom Movement. I'm a movement guy, and I just love the idea of being able to contribute collaboratively to help make the world a better place by using technology. So, every time I google for something and hit Wikipedia, I can't resist trying my best to make an entry a little bit better. It's the Free Software hacker in me.
I kind of like that I came to Wikipedia (and by extension, Wikibooks) way late; I only started ever editing pages a few years ago. It's just beautiful to see such a wonderful community dedicated to helping people learn flourish in this way. It makes me all the more proud to be a free software guy to see that community inspiring others to do amazing work of their own.