I have found that as I've gotten older (I'm 50 now) I tend to read more of a balance between fiction and non-fiction. I think it really depends on the person and what they like to read, or what they need at the time. In college, because I majored in creative writing and English Lit, I burnt myself out on fiction. There was a five year period after that where I couldn't bear to read fiction. So I read exclusively NF. Some years I read more fiction, other years more non-fiction. I love biographies, true crime, and self-help, but I also love a good horror novel or a cozy mystery series. Sometimes even a romance or a solid fantasy or urban fantasy. I've even been known to pick up women's fiction and literary novels. Depends on my mood. If I need to escape, I read more fiction. If I'm feeling more curious and contemplative, non-fiction tends to be my choice.