I definitely needed to read this one twice. It wasn't the type of book that was meant for me to be reading when I'm tired, because it addresses a part of my brain that I'm not really used to using. I definitely asked for help on how the systems work, because I was trying to understand the book. I think kids might figure it out more readily than I would, and most likely they would be building models to figure it out, rather than trying to visualize in their head. The idea of a sloth escaping was continually funny to me (so much effort!).