I know I sound like I'm obsessing over this, but chronic lack of sleep is a creativity destroyer and anything that messes with my creativity is bad. It's all I've got. Plus I've seen someone with severe sleep deprivation and I never ever want to be like him.
Way back in 1993 or thereabouts, I temped for about six months in UT's Federal Programs office. (I started drawing snarky comics about work at that time and published them in the zine Temporary Insanity, incidentally, but that's beside the point.) While I was there, my boss was working on a big huge major grant, which is not a simple process. There's a lot of paperwork involved, including gathering some 50+ letters from various important individuals telling the government why UT deserved the grant and not some other university.
Well, while he was working on this grant, my boss apparently decided he could get more done if he stopped sleeping. I saw him go from an affable, intelligent, reasonably organized guy to a gray-faced automaton who kept losing things. I had to retype a lot of stuff for him because he couldn't find it. His organization skills went down the toilet, and he lost his sense of humor entirely.
He also lost all those letters. Every one. They never turned up. And he lost them about one week before the grant's deadline, which meant he had to call all the important people who'd sent a letter and ask them to resend it immediately.
Don't be like that guy. Get some sleep.