Sleeping is..complicated for me. Not actually sleeping as that's usually fine, but falling asleep can be troublesome. I have to be tired to fall asleep. I can't force myself to sleep whatsoever. That's why christmas eve was always torture for me. Basically, if I lie down and I'm not tired, my mind wonders. Endlessly, aimlessly. Like entering a mental void that quickly becomes occupied by way too many thoughts. I've had nights where I would legit go from feeling fine to being near a panic attack because there's too much going on "upstairs". Upon which I have to get back up and focus myself onto something, anything. If I do fall asleep when I'm not tired, I'll get a few hours at best and then I won't be able to do the same thing again that night.
So I guess that is why I "procrastinate" doing so. My mind won't let me unless I'm too tired to think.