I had a rather rustic upbringing--reading was often my only diversion. When unread books were scarce, I had to invent entertainment for myself. That's how the writing seed was planted.
I enlisted in the military right out of high school and volunteered for an elite unit, hoping to experience some real-life adventure. I guess I did, but nothing like my naive imagination concocted.
Throughout my life I never lost my compulsion to write. No matter what kind of situations I've found myself in, my brain never tires of milking story ideas out of them. I couldn't stop it if I tried.
Growing up, I read mostly to escape. So I liked adventurous fiction the best: space opera sci-fi; time travel sci-fi; sword & sorcery; war novels; paramilitary thrillers; action adventure or "men's fiction;" mysteries including whodunits AND hard-boiled. I never paid much attention to critics or even names of authors--I just read whatever held my interest...and then read it again.
After watching John Ford's film The Searchers, I added westerns to the list of genres I read (and wrote) in. As I matured, my tastes grew a little more sophisticated. But just a little. I still can't get into Shakespeare and many of the classics, but then I also have a lot less tolerance for formulaic plots, pointless plots or lack of plot, bad dialog or poor writing in general in the aforementioned genres I grew up enjoying so much.
I'm still not "trendy" by any stretch of the imagination. I know, for instance, that vampire fiction is hot right now (and Harry Potter and anything by Stephen King is always hot), but I still have no desire to read that. Seems like amazon superninjas are obligatory for any action adventure (whether film or book), but I'm well past sick of them.
Oh yeah--I've read tons of non-fiction, too.