Optimal Hours to Work

For some reason, I work best during the day and late at night.

I am talking about 8:00am to Noon and then from 11:30pm to 2:30am. The hours in between Noon and 11:30pm, are the worst times for me to do any learning or studying. It doesn't matter how much "will" I have during the afternoon, my brain won't cooperate. I can sit there and look at the book, but the brain will not absorb it. I am beginning to think I have attention deficit disorder and should consider taking some medication. Maybe then I can buckle down and learn what I need to learn in shorter amounts of time.

Alternative? Take a nap, you say? For that to work, you'd have to assume that when I do wake up from the nap I won't be even more lethargic. This could work, I'd just have to find a way to keep the sunlight and heat out of my room. I don't know why, but just the midday environment makes my mind stray and wander all over the place. At night, when it's dark, I feel like I can zero in on my task and complete them more readily and easily.

I know I am not alone. What is it about being able to get things done more easily at night?