Not getting enough sleep impacts your ability to focus. It makes it harder to stay on task and come up with new ideas. It also affects your ability to make decisions. Like, you know when there’s something that you need to do, but you keep deciding to watch Netflix instead? Getting enough sleep can help with that.
If you get enough sleep, your work will be better, your focus will be better, and you’ll have more willpower. All of this stuff leads to better self-discipline.