When I was a child, non-fiction didn't appeal to me very much. The point of reading (other than learning things for school) seemed to be reading stories. If it wasn't narrative, I wasn't particularly interested, unless it was something I needed or wanted to learn about. History sometimes worked for me, since most history has some sense of narrative. But I had a complete lack of interest in most forms of non-fiction.
Then I got older. My interests expanded. Suddenly, non-fiction didn't seem so bad. I was a teenager when a book my mother had bought on a whim, one about teenage girls and bullying, sparked my interest. I started to read. I had never been bullied, but I was a teenage girl, and I was suddenly curious. I don't remember the name of the book now (just that it wasn't Queen Bees and Wannabees, which I read a decade later). Whichever book it was, that was the one that made me realize that non-fiction was not boring, so I am grateful to whoever wrote it.
Today, the non-fiction section is one of the first places I go when I get to the library. I'm more likely to check out a non-fiction book than a fiction one lately. My love of narrative remains--I read a lot of memoirs and a lot of history--but I don't limit myself to fiction when I read. It's been a gradual process, so that I can't really pinpoint when non-fiction became my first destination at the library, but it's led me to a lot of interesting reads.
I haven't abandoned fiction; I still love narrative and there is something ineffable about a well-written novel that I rarely run across in most non-fiction, but non-fiction opens up worlds of words and thoughts that don't always make into fiction (or at least into the fiction I end up reading).