People cannot live by fiction alone!
Okay, okay, they can – and I do. I used to read a bit more non-fiction in my younger days and especially during my school days. And I read a fair bit while keeping up with what my kids were reading while they were in school so that I could get them to learn to converse about what they read, especially since many struggle with non-fiction books. So many given to kids to read tend to be so dry or uninteresting that it turns them away from it entirely!
That said, I personally don’t have a favorite non-fiction book overall so I’ll leave this one wide open to the readership to dominate with.