"Be intense about things that matter, super laid back about everything else"

That is the advice from Ben Casnocha, who notes that some of the things he chooses to be intense about are relationships (family and friends), work, and personal development / learning.

One time I tried writing down and prioritizing the things that were important to me. The results were surprising, at least compared to the amount of effort I devoted to the things that matter. I think it is deceivingly simple to lose perspective on what is important, which I why I think having an explicit, written list of what matters to you, and re-visiting it frequently, is one of the best things you can do for yourself.