Even "comfort food" (or the equivalent) can expand and exercise your thought. I read a ton of what even I consider "fluff". Science fiction, fantasy, mystery,

Even "comfort food" (or the equivalent) can expand and exercise your thought. I read a ton of what even I consider "fluff". Science fiction, fantasy, mystery, adventure, horror. Novels that get unceremoniously lumped under "genre fare". But even if the primary motivation is entertainment, I can honestly say that from a young age, reading lots of anything exposed me to new ideas, ways of thinking, and perspectives. Even something as simple as spelling and vocabulary seem to come a lot easier, if only due to having seen so many words written out over time. I remember being a kid and never really having issues with spelling or knowing most words because I'd at least run across them already. That's not to say reading more "serious" material is useless. It just isn't an either/or question.