There's a difference between a design that you use the first time and a design that you use all the time. It doesn't make sense to change the buttons just so you can figure them easier on the first time (I had no problems by the way with it). When I'm spending large stretches of time reading I actually enjoy having the buttons on each side go to the next page. I'm not staying in the exact same position as I was an hour ago, or maybe the same side. If you're lying somewhere you want to spend as little effort as possible just to go to the next page.