I've wondered this for a very, very long time. Like high school time. And I'm 22. At least it feels like a long time.
Either way, a lot of my interests begin to solidify at that time. That was where I discovered the "-punk" subgenre of science fiction, particularly the retro-futurism derivatives. You know, steampunk, dieselpunk, atompunk, you name it. I had a fascination with film, but it was then that I discovered the art and sophistication of the medium. The same went with literature. In fact, it was in that that I realized how interconnected it all was. Applying literary analysis to film? Who'da thunk?!
I really like thematic complexity. I like fiction that makes me think about things. A lot of those works also happened to be pretty dark. But I don't mind. I also like me some imaginative, weirder stuff in my science fiction and fantasy.
So why do I keep thinking I'm some weirdo creep that no one would want to hang around?
I remember when was I was reading The Hunger Games while dealing with depression. I was told that I was negative and sad because I was always "reading dark and depressing things." I still find myself thinking about that. Is it what we read that makes us feel this way? Is it an unliving, inanimate, bound stack of paper that makes you want to consider suicide?
Or is it people who blame a mental condition and hazardous side-effects on said stack of paper or millions of pixels on a screen?
I don't know. I guess it's subjective.