There's different styles to it, depending on where you live, how your life is, and it means to "live your life" for you. E.g. you could have certain periods where you work really, really hard, and then you take a longer break, month, 3 months, 6 months, etc. Or you could work really hard to try and get an early state of financial independence. At that point living life becomes very easy, because you know you can just quit to do whatever you want, you are not dependent on anyone else so much less stress. Otherwise job market, your company state, leadership etc will be unnecessary stressors.
I completely agree but I will say that as somebody who intellectually understands that principle, overwork and burnout are still insanely common and arguably even rewarded in some work cultures / tech in general, and I screw this up a lot.
Even people who understand this rule / philosophy end up violating it if they're not careful.
... and with that I think I'm probably going to sign off for the day. It's late.