The lightbulb just went on for me as well. My DS6 used to devour picture books as a toddler, but now that he is reading independently, I've found it challenging. I'm always trying to encourage him to pick up longer story type books at the library, but he tosses them aside and goes for the non fiction books with lots of pictures and large text. Even though he can easily read Magic Tree House, he usually stops mid page and asks me to read it to him. I never thought of the mental image and connection. Thanks for opening my eyes!