What did I do with this book?

Last night I found the missing book. Yeah, that's right, it was in a place that I checked at least 2 or 3 times and didn't find it. It was in the rolling suitcase that's chocked full of Tunisian books and samples for the Tunisian classes that I was teaching. I had set the suitcase aside so that I can sort the books and get them onto the bookcase, and get the samples organized so that I can set up new classes.
The Essential Crochet Techniques book has in the center of a stack of Tunisian books, why did I put it there? Why didn't I find it when I looked in the suitcase? Another crochet mystery!