Something I realized recently: "anything can happen" is pretty frightening to me as a reader. It's why I don't really appreciate the genre of science fiction. Science fiction to me means that the author asks me to suspend disbelief, to accept whatever outrageous occurrences take place. It means that the author creates a new set of rules for the book's setting yet is free to change those rules at any moment. Sci-fi as a genre is by definition implausible, which is something I can't stand in books. Add to that a preoccupation with germs or advanced technology (both topics that aren't really my thing), and it's understandable that I've never read a science fiction book I've appreciated.
Science fiction in theory, though, is something I love. The recognition of the vastness of the amount undiscovered. That the imagination - no matter how wild - may never be able to fathom it all. That the moment of discovery can change everything.
Yet somehow, I've never read a science fiction novel that captures that immenseness and strangeness and uncertainty. (See: preoccupation with diseases and computers.) It's the good fantasies that seem to capture that, maybe because the stakes are higher in fantasy. Maybe because the implausibility of "anything can happen" is limited in fantasy, because the worlds, while different, have rules, and they follow those rules. Magic has rules. Countries have borders. Not that plots cannot have twists - of course they can - but the twists need to make sense within the context of the story, not occur simply because they can. In those cases, twists come across as cheap manipulation.
Opening a science fiction novel, in that sense, is a big risk for me as a reader. It's like asking me to walk a tightrope without a safety net, to risk caring about characters who by definition are never safe. Because when anything can happen, no one is safe. And while that bears a frightening similarity to life, it's not why I read.