Well, I guess that's one of the perks of the curse of multitasking. I sleep next to two books minimum, and decide on the fly which of them I wanna read at the time. It is actually quite easy to not lose track if only you're involved enough.
The short stories I pick one at a time, usually, and finish 'em when I'm not interrupted by other things. They pile up a bit when I do get interrupted, though...
I ain't an ordinary person.