Nobody Cares About a Few Million Nanoseconds

The "Nobody" in the title is a link-baity exaggeration. There are programmers for whom a few million nano-seconds do matter.

Certainly they matter for high-frequency traders. They certainly can matter when they're embedded deep inside heavily looped code. Hell, there are times when it they even matter for me! And when they're in heavily used libraries, you simply don't know.

So he weasels out of it at the end by saying OK, it doesn't matter 97% of the time (which is a remarkably accurate figure (He claims Knuth said it, Knuth attributes it to Tony Hoare, who in turn disclaims it)).

But while the detail of the sentiments might be true, the title is a lie.

The real lesson is to understand about these things, and deal with them in their due priority. Don't sell me short my assuming I'm too stupid to understand.