As I get older, my ability to sleep through night and go back to sleep if I wake up in the middle of the night is diminishing. There are many nights when I wake up at 4 am and just know that I am not going back to sleep.
On those nights, I get up and work on things on the computer. It makes for a long day, that's for sure.
So I am thankful for those nights when I wake up and look at the clock and it is 6 am and am grateful I slept that long!