[nsguy]

This quote is often taken out of context, here's the full quote: "Programmers waste enormous amounts of time thinking about, or worrying about, the speed of noncritical parts of their programs, and these attempts at efficiency actually have a strong negative impact when debugging and maintenance are considered. We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. Yet we should not pass up our opportunities in that critical 3%."

If you want a specific example look at something that needs to be performant, i.e. in those 3%, let's say OpenSSL's AES implementation for x86, or some optimized LLM code, you'll see the critical performance sections include things that could be reused, but they're not.

Also the point Knuth is making is don't waste time on things that don't matter. Overuse of DRY falls squarely into that camp as well. It takes more work and doesn't really help. I like Go's proverb there of "A little copying is better than a little dependency."

[rgrmrts]

Knuth was talking about a very specific thing, and the generalization of that quote is a misunderstanding of his point.

Source: Donald Knuth on the Lex Fridman podcast, when Lex asks him about that phrase

[nsguy]

I wasn't aware this was discussed, thanks for the pointer! I'm curious now what he says he was talking about ;)

[nsguy]

Here's that segment: https://www.youtube.com/watch?v=74RdET79q40