My son loves these books. I currently call them the 'forbidden books' and are kept in his closet's top shelf. It is such a treat for him some days when he asks to see them. He is fascinated by the pop-ups and loves to look at them. Yes, he is definitely under supervision at all times when handling these books ! I am so glad I started to purchased them so early. The books have also taught him patience and respect for delicate items. Although, I'm sure if given the chance he would pull the pop-up apart to see how it works. I have purchased all of my pop-up book second hand; in the past two years I have only been able to find four other books by the same author.