Don't ask me how, but I once accidentally put both the Parker Complete Savoy Vol. 2 CD and the Stan Kenton Contemporary Concepts CD at the same time into the Parker jewel box.
So one day I'm surprised to open the Kenton jewel box and find it empty. I figured that it must have accidentally gone out in the trash and that I would one day have to buy it again. Some months later, I took out the Parker CD to play it, and there was the Kenton too!
There have been occasions when I couldn't find a CD. I keep mine using the LIFO method. But so far the ones that I knew were missing have shown up. They were on a shelf I usually overlooked.