I also think in many cases comments serve as a stand-in for poor design. These days, when I catch myself writing a comment, I try to think of whether I could choose a better name for a variable or method instead, or if I could add an assertion to clarify that an invariant holds in a particular location. Comment rot also makes ordinary code rot look like a walk in the park. Since comments aren't tested, they rot incredibly quickly without meticulous double-checking every time you modify the code. In a heavily-commented, older codebase this become super annoying, since every other line is a comment that, ten percent of the time, doesn't hold any more.

JS is full of fun facts, like that ++ is different than +=1, or that ToInteger may return negative zero.

Better naming can't justify these head-scratchers. As an implementor all you can do is write a loud! comment! referencing the spec, and add a test or two or a million.

Anything that implements a spec needs copious comments to justify the implementation. clang for example is chock-full of references to the C99 standard.

I think the problem of stuff going out of date can be avoided by giving background (why it was originally written) rather than making a commitment you can't keep about keeping it up to date.

Knowing why code was originally written can be more important than knowing what it currently does.

Great advice, and it does resonate. FWIW I'm certainly not a "no comments" guy. I just like to check myself to see if there is a better way to accomplish what I was going to do with a comment.

This is fantastic advice.