Happens to me all of the time. . .
Of course, I work nights, so I tend to stay awake during the night. I'm on my 3rd of 4 days off. I'm here wide awake, typing on this stupid computer keyboard and also working on some music. . .
Many times, though, that usually is the culprit (sp?). . . music. . . especially if I'm writing it!
It's in my head like an echo heard in a long, deep canyon. My wife has the same problem. If she's working on a show, she lies awake just "hearing" the music in her mind.
Oh well. . .
What do I do to get some "sleepy eyes?" I just get up and work on the music most of the time. Amy, on the other hand, reads. She has literally dozens of books . . . all romance novels . . . that she reads and re-reads and re-reads . . . all the same few books. It helps "shut her busy mind" off so that she can sleep. Works too! (Except that she calls out all of these men's names during here sleep! ! !. . .
Hope you get some sleep so that you're awake to enjoy your day off!