books on cd/tape vs. books

I'm a librarian so it's obvious I love books. I love to hold them, I love looking at the words and I love being able to read the words faster than I can say them.

My mother-in-law likes books on tape/cd and frequently passes them on to me when she's finished with them. I love listening to them on my rides to and from work. The past few days I discovered a major problem with listening to the books. You can't "accidentally" sneak a peek at the end! I've been listening to a mystery and I decided about an hour into it that I knew what was going on and who the bad guys were but I couldn't confirm it. Now I'll have to wait patiently until I get to the end to find out if the husband has been setting the wife up. It's not like this is the best story in the world and it's definitely not something I would have read but I'm invested now and it's driving me crazy!

It's a rough life.