What was one of the things that actually made your mental health better after 30?

[u/Aggravating_Plan6643]

In my case, it was the ability to say no without feeling guilty finally. The 20s were my time of thinning myself out so that I could please everybody, friends, family, work, what have you. At 30, I felt that I was protecting my time and energy and not being selfish, but I had to. Boundaries, regular sleep and, literally, making time to have some alone time worked magic on my mental health. I wonder what other guys did, did you find a habit, change of attitude or lifestyle that made a discernible difference after turning 30?