My sleep cycle has once again changed with a new decade of life.
When I wake in the middle of the night (usually at the 4-hour sleep cycle end), I actually enjoy my time -- either watch Jon Stewart -- recorded at 11, when I'm almost always asleep or about to fall asleep, or I read, or I get on the computer -- now my iphone -- for a half hour or so.
If I'm really sleepy, I'll warm some milk, maybe add some kahlua (yum) and take it back to bed with me. My cats are very patient with my new habits. When I go back to sleep, whether it is after a few minutes, or a half hour, or sometimes after a whole hour, I usually have another deep sleep for the (needed) period of time... I can't remember when it was last necessary to use an alarm clock -- if I need to wake up particularly early, I let my brain be aware of that (or drink a little bit extra the night before -- native american alarm clock style). It's me new older-woman schedule. I also consider it my naval schedule -- Ship's schedules had sailors sleeping 4 hours, awake 4 hours, sleep 4 hours, alternating watches. When I was little, my ambition was to go into the navy and sail around the world, before I found out women couldn't do that -- then when I turned 18 they could, but by that time.....Vietnam, and so many other callings to me.
Many sea captains, sailors' wives, lighthouse keepers, ship-makers in my ancestry. I honor them with my new sleep habits.