Year after year and decade after decade, I keep relearning the same simple lesson: I know how to program computers; I can write a 20-line function rather than try to integrate a huge library with many huge dependencies. Some day I will actually internalize it.
Related: on my current project, when I type `bin/server` and hit enter, it's listening for HTTP connections after about 600 ms. It's very nice.
"Programming should be like putting Lego together; just decompose everything into tiny pieces with maximally general interfaces!" sounds great. Then you fast forward a decade and simple tasks have become wildly complicated, sometimes breaking for reasons that no one understands.
Every trade-off gets caricatured when it meets the broader culture. And "writing code that's theoretically deferable to a library means you're NIHing" is a more reasonable extreme than "just rewrite everything from scratch", so we get the former. But the middle is what you want.
"Should I spend a full day integrating a library that might go unmaintained in two years, when I could write a 20-line function that I'll maintain myself?" Almost certainly not. "Should I implement time interval calculations where I need accuracy to the second?" DEFINITELY NOT.
I guess this is the moment that I have truly become An Old Programmer because here I am shouting at clouds about trade-offs. 
