Do you ever read more than one book at once? If so, do you get plots/ characters confused sometimes?

I’ll often read more than one non-fiction book at a time, but I can’t do this with fiction for exactly the reason you mention.  I enjoy fiction the most when I’m completely submerged in its world.  If I jump out of that world and into other worlds, I lose both my memory of the fine details of that world, and also the momentum that carries me along with the story. 

Momentum is important.  I’ve abandoned a ton of really good books over the years because life became too busy to give the book my proper attention.  That’s the funny thing about a book—sometimes you encounter it at the wrong time of your life, and it doesn’t draw you in, but later you find it again and it’s a revelation.  The book is the same, but your ability to enjoy it has changed.  Sometimes, instead of writing off a book, it makes sense to file it in the “try again later” slot.

I think that mysteries and thrillers are particularly hard to enjoy in tandem  When an author plants clues, he tries to make them difficult to spot for even a closest reader.  If you’re reading several other books at the same time, you almost have no chance.  I imagine that every new homicide case makes it harder for a detective to complete the cases he’s already working.  It’s no different for readers.

There are some incredible readers who can move effortlessly amongst a dozen worlds at the same time.  When I was younger, I was better at this.  I think it’s easier to do this with books from different genres.  If you’re reading a fantasy book while you also read a mystery, you’re unlikely to confuse a wizard for a special agent.  I wouldn’t read all of the Harry Bosch novels at the same time; if anyone could do that and keep all of the characters and plots straight, they should get to be President.

Every writer envisions the ideal reading scenario for his book; a quiet room with good lighting, devoured in long sessions over the course of two or three days.  Some people will read like that.  Other will read on airplanes, or buses, or trains; they’ll read five-minutes here, and another five there; they’ll read during commercial breaks; they’ll read in tandem with another book (or two, or five).  I may want someone to linger over every clever line I stuck in The Bubble Gum Thief, but that’s not the important thing.  The important thing is for the reader to enjoy the book.  (Frankly, if they stop to think about whether I’m clever, I’ve failed as I writer, because I’ve taken them out of the story and made them remember that they’re reading a book, and not just observing a world.)  And if they enjoy the book, it doesn’t really matter how they read it.