One of the biggest struggles people face is getting enough rest. Without enough time in deep and REM sleep, you end up lethargic and exhausted day after day. And if you're sleep hygiene's out of control, those blissful hours or dreaming will continue to elude you.
Everyone pulled all-nighters when they were younger. Writers often attempt to do the same. When inspiration strikes, you lose track of time. But sleep's valuable - and wasting it comes with a price.