Anemia is what usually does it for me. When my iron gets low, I'll start sleeping better for a while but then I'm still exhausted. That's when I start eating more meats and taking iron supplements to get it back up. It usually takes about two weeks for it to get back to normal.
Oh, you will. It is all a dream and since matter cannot be created nor destroyed, the dreams must be real in all their myriad forms. -Beowulf
This Delicate Thing God Has Made
The world is measured in peasants; smaller than a unicorn but, bigger than a tidbit!