Has your sleep cycle changed over the years as you have gotten older?
I used to be an early bird. I would be in bed by 10 pm most noights and be up at 6 am. Sometimes in the early after noon I would take a half hour "power nap" to energise myself a little.
Ever since I started working nights (a little over 2 years ago), my sleep patterns are completely wacked. I don't get to bed untill 2 or 3 am, sleep untill 6 am, get Roo up for school and lay back down around 7:30 am after he leaves. It then takes me a good half hour to relax enough to get back to sleep even though I am still really tired. I get up again between 10 and 11 and once again lay down for a hour nap around 3.
I have found that I can no longer sleep more than 4 hours at a time, even when I do not have to be up to send Roo off to school. Even while I am sick, unless I take benedryl for my allergies, I am up within 4 hours of going to sleep an cannot get back to sleep for at least an hour afterwards.