The person talking in the video is Jocko Willink [1]. He's written quite a few books, one of which is entitled "Discipline Equals Freedom: Field Manual"[2]. His whole concept is that increasing your discipline leads to more freedom.

How can one be free when they are a slave to their discipline? A great example is time, everyone wants more of it. The way to get more time is to not waste time. Being discipline with ones time is how not to waste it.

I'm far from the most disciplined person (practicing discipline is pushing the rock), but in the ~2 years since I really put more discipline in place it has changed me as a person. Highly recommended.

[1] He has podcasts, and many books. I suggest listening to Tim Ferris when Jocko was on as an intro.

[2] https://www.amazon.com/Discipline-Equals-Freedom-Field-Manua...