I remember reading somewhere (sorry, no link) that waking up at the midnight, and then going to sleep again after an hour or so, was considered normal a few hundred years ago. Now this habit is gone, probably because we make the night shorter using artificial lights.
Yes. I know. See e.g. http://en.wikipedia.org/wiki/Segmented_sleep I knew that beforehand. That was the reason I wasn't worried when my children woke up at night and crawled into our family bed (some other parents seem to worry.about the quality of their childrens sleep).
But I'm surprised that he actually segmented and that it went this far. I understood that artificial lighting - and we have enough of that - suppresses this segmentation.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.