I call it cheerful nihilism (also the name of a fun facebook page), and I compartmentalize the shit out of things.

It's hard to explain, but basically I have such a long view of things these days, while I totally agree with what you said about not half-assing and not disappointing people by being unreliable, it really helps with all the external bullshit to know none of it ****ing matters in the grand scheme of thingd.... like the memes showing the Milky Way and a little arrow, "here's you, crying in the shower before work".

And that's not to say I don't get discouraged by shit out of my control or that I brush off other people's difficulties, but just the idea of enjoying your miniscule 80 or 90 years on this planet while helping others do the same (yet, hopefully not letting one get in the way of the other long term).