I used to read Stephen King, bought every single book and read it at once. But for a while I only need to pick up a book and I fall asleep. This happens with real books made from paper as well as with the ebooks we have. One page is the longest time I can read before my eyes get closed and I have no chance to stay awake.
That's a shame because I have 3 or 4 of the latest Stephen King books in my shelf and reading only one would last a year or so :(
Maybe in a few years, when I'm retired and I can read at any time it will be different...