I realized my book was missing and drove 3 exits back to the lot
When did you realize it was missing?
I was searching in my car when it hit me.
Well, I'm glad you remembered you left it!  When you forget something important to you it's important that you go back and get it, or you'll end up regretting it!
True, I feel great now.
I can't even begin to tell you how many things I have lost over the years. I wish I had noticed as early as you had in some of those situations. Can you tell me what the book is about?