I read plenty of YA books. Started reading adult books at about 7, I guess (anything that wasn't a picture book was my motto), so I sort of "set" my reading habits then. My parents were also readers and had sort of blinders as regards to books. Nothing was off limits. . .in a book I found in our house. So I read Reader's Digest Condensed books (my grandmother's) and Charles Spurgeon's Sermons (my dad's) and the Little Women series (my mom's) and Stephen King novels (my brother's). Along the way, I got books at garage sales and book warehouse sales and scarfed them out of the homes of dead relatives.
Nowadays, if it looks like I would enjoy it, I read it, stated age be damned. I make no apologies.