Willpower is a finite resource.
Willpower is finite, a muscle to be exercised, and can be rapidly depleted depending on your morning outlook, habits, and daily decisions.
I could discuss this in multiple posts and it's a topic that has touched my life. If you are feeling like you are reaching decision fatigue in your life, I would recommend reading books and watching Ed Mylett's video on taking massive action.
If the first action you decide in the morning is hitting the snooze button, you've already decided how your day will roll. If you have 100 units of decision power and you spend 20 getting out of bed, you will likely perform subpar at your job, and exhaust all your units by bedtime.
Why is this important? Because if you have 0 units of decision will power by bedtime you will likely not go to bed at a consistent time. Why? Not because you aren't a responsible person, but because your exhausted mentally. Your mind just wants a break and desires some semblance of freedom.
Many posts I write focus on morning habits which bring dividends in the evening. If there is a habit that I could instill to maximize your decision power it is establish a consistent bedtime and never, ever, hit the snooze button.