Because apparently, I am only allowed to do one or the other, but not both.
For the last three months or so, I have been trying to read Anna Karenina as well as Making Mondragón (examining the famous Basque cooperative). I misplaced Anna Karenina, so I turned my attention to the other book. Then Mondragón went walkabout... and the next day I found Anna Karenina. I read it for a week or two, and then forgot it somewhere during a day's jaunt. Now I had neither… Except that, a couple of days later, Mondragón turned up again. I lost that again several weeks later and… You guessed it: Anna Karenina turned up very soon thereafter. This week, when I misplaced Tolstoy, I joked with my wife that now Mondragón would turn up. What days later, I picked up a bag I had not used in a couple of weeks, and there it was.
I guess if I need my copy of Anna Karenina back, I am going to have to deliberately misplace Mondragon.