The three types of control:

Things that you cannot control, you cannot control so it’s a total waste spending time worrying about them.

Things that you can control, such as your thoughts and actions, you should worry very deeply about. By practicing meditation, you can practice placing a buffer between an action happening and your reaction. Your actions are the result of your thinking, and your actions cause habits, so being able to control your thinking to not be reactionary helps build good habits.

Lastly, there are the things you have some control over, such as the amount of practice you put into gaining a skill. These things you should also worry about, because you affect the outcome either way.