Fast forward one month. Since the pair I'm currently wearing are still in fine shape, the new pair is still sitting in the box in the bag I brought them home in. I was doing some tidying up this weekend and figured I should probably at least take out of the box and make sure there was nothing freaky wrong about them that would require returning them. And what did I find the bag? the missing fifth notebook!!! I must have been jotting down ideas as I was walking down the street and just stowed it in the most convenient place as I entered my building.
So, the transcription and (hopefully inevitable) novel writing shall continue.