"Is this book about you?"
Contemporary writers get asked this question a lot, I assume more so than other writers. I doubt J.K. Rowling has been asked whether or not she is secretly part of the wizarding community. (Though many people did assume Harry was based on a real person.) It seems that some readers have a hard time believing that characters, and their situations, are actually fictional.
But they are.
I grew up in a small town in Arkansas, and I've lost count of the number of people who've told me they tried to figure out who my characters are in real life. My characters are based on no one and everyone. I've never modeled a character after anyone, but I have used what I know about the world to hopefully create dynamic characters.
I wrote a guest post about this back in October, but I thought it was worth mentioning again. Pops is not my grandfather, and I don't write my students into novels.
But characters are real, in the sense that readers make them so. And isn't that the best part about reading?