I have existential depression. Or at least that's what Google tells me. Pretty close to nihilism. I don't believe life has any meaning. Hence I don't find anything worth doing. Yet I still do stuff. But life is depressingly hopelessly empty.
I try to pull what little joy out of life that I can. I think the only things that matter are what matters to us living things.
The best way to live your life is a type of compassionate hedonism I'd think.
Some things with too high a cost/reward ratio, like 10 more years of a college or something, I just won't do. I'm going to be dead in 50 years anyways, so what's the point?
Learning a new programming language? Maybe, but only if I like the language. Luckily I often enjoy learning.