When you go to the army, the first thing they teach you is to make your own bed.
Before you do anything, you make your own bed.
It teaches you to take responsibility for your life. No one else will make your bed for you.
It inculcates the habit of doing the small jobs properly. That habit pulls into more important parts of life as a soldier, ie: not dying.
It gives you a small win to start the day. Being a soldier can be extremely demoralising and stressful. Dodging bullets is not fun. Every little win counts. Start the day with a win, and the rest of the day is easier.
Entrepreneurs are soldiers.
Make your bed in the morning.