a senior moment...?

A couple weeks ago I ordered some books from Amazon about photo documentation and portfolios to get some more information about some of my areas of interest in the classroom. Two of the books were straight from Amazon and one was out of print so I ordered a used copy from one of their affiliates. The books from Amazon came shortly after I ordered them and I skimmed through them and added them to my collection, and as I remember it, the third book came a few days later. I was really excited to get the final book, as I'd been very curious about it, and I remember being very excited when it arrived. I remember taking it up to my room and opening the package, flipping through the pages, and planning on coming back to it later. Then I couldn't find it. I'd done some cleaning around the same time and thought maybe it had gone out with the trash--I searched my room multiple times and even went out back to the trash cans to see if it had ended up there--the trash had already been emptied, though, and I figured it was gone for good, and I'd have to order another one someday. Today there was a package waiting for me when I got home. I was excited and intrigued because I wasn't expecting anything. I opened the package, and it was the book I had ordered! It didn't look anything like the one I thought I had lost (so there's no chance that they accidentally shipped me two). So now I'm thinking, either I recieved some type of book/booklet in the mail which I proceeded to lose, but have no idea what it was, or I dreamed up the entire thing. Both are pretty scary. I think I'm losing my mind...