Some of my comics seem to have gone missing. I'm sure I own the Hitman and Hitman: Local Heroes trades, but currently I can only find Hitman: Ace of Killers and Hitman: Who Dares Wins (the latter a recent purchase). Likewise, I'm positive I own at least the first and maybe the second Starman trade, but can't find either in my collection.
On the other hand, it appears I own two copies of Sandman: Season of Mists. The same edition, even. I dunno how that happened.
I really need to reorganize my bookshelves so my stuff isn't "organized" in piles on the floor.