[andai]

I can fall asleep in the afternoon (3-7pm) but I usually decide to stay up later, so I don't wake up fully rested in the middle of the night. As a result, by the time I finally go to bed at a normal hour, I'm wide awake and can't sleep for ages.

[dijit]

This must be a common problem, I have exactly the same situation.

Someone once told me that you get tired when the body warms up, which makes some sense if you are one of those who goes from a cold outside to a warm inside.