The 80-20 principle applies to pretty much anything you can think of in your brain organ right now. Anything you give heaps of fucks about, do it, give 80% of fucks about it, but leave 20% in reserve. Understand that that thing you give a shit about, isn’t everything, and it can easily change (for better or worse).
Even if it’s something you have total control over, giving 100% of fucks about something is the surefire to become fanatical, unreasonable, stubborn, shot-off from learning, and basically just a complete dick about something.
When we live in a world with others who sometimes are trying to at most moderate, get something from us, or at worst exploit us (or even worse), and with the unpredictability of nature, giving 100% of fucks about something is not only unrealistic, but it’s also dangerous.