I can't, unless it's impossibly engrossing (the last one was Here Burns My Candle, a Scottish historical novel by Liz Curtis Higgs).
Really, though, I think I read multiple books at a time because real life has many parts. I am more than just a learning brain: I am also an imagination, a soul, and a body. I am a worker, a server, a dreamer, a pilgrim, and I stand in need of beauty as well as instruction. I read multiple books simultaneously for the same reason I schedule more than one type of activity into my week. I lesson plan, but I also watch movies. I have coffee with friends, but sometimes I'm alone in the quiet house. I spend time both praying and walking. We are whole people with multiple areas of life, and each of those areas has different needs.
I suppose you could call it holistic reading. The good part about it is when I have a moment to read, I almost always have something I feel inclined to read right then, no matter what time of the day or week.
Just as I sometimes schedule too many activities into a week, however holistic they may be, sometimes I take on more reading than I can actually handle. Ever have that feeling? The spines look so pretty, all fitting snugly together on the shelf, until you realize you haven't opened any of them in a week. Or more. And that even when you do snag a stray hour for reading, you spend a quarter of it in paralysis before the bookshelf, worrying and wondering over which volume you should spend the time on.
Right now, for example. It started out as a very holistic plan, with some books for each different area of life. It went like this:
Island of the Blue Dolphins by Scott O'Dell
Hatchet by Gary Paulsen
A study on the book of Isaiah by Navpress
Grace for the Good Girl by Emily P. Freeman (who, by the way, has a great blog: http://www.chattingatthesky.com/)
Phoenix Feather by my dear friend Angela Wallace (angelawallace.wordpress.com)
The Pilgrim's Progress by John Bunyan
101 Famous Poems (see "Why Busy People Need Poetry")
Whoops...suddenly I'm reading 7 books. And my "To Read" stack is still growing.
Perhaps there's balance to be found in this reading mania. There are so many great books to read, each equipped to meet different needs. Maybe the key is to limit the number of categories...and the number of books per category...and the number of times I say "yes" to a new book...
The challenge is to remain holistic without becoming overextended. Sounds a lot like my life.
What are you reading right now? Do you have a one-book-at-a-time policy?