While this is indeed a very good advice, I learned how to cope with this a little better than “just don’t care”.

Mostly because I do enjoy coding, and am still sentimental with code I’ve written decades ago. The trick is to split that kind of code into their own libraries. Preferably open sourced. This way once your code has outlived its usefulness to your current project it can still live on, and be useful somewhere else.

For example one of the first things I’ve written as a jquery plugin that I really liked, I polished it, wrote some docs and demos, and in its day it was pretty cool (stayed on HN homepage for two days). I still got mentioned for it years later by people actually using it even now.

Even if I myself don’t find it useful at all, it’s still nice to see it is used by someone somewhere.

I’ve had customers request complete rebuilds of functionalities several times over, destroying weeks of effort each time… and I’ve never cared, as long I’ve clearly communicated my concerns beforehand.

I’m precious about the code only while developing it. The process is the fulfilling part to me, not how the end result is used. The approach has its drawbacks, I’m sure, but I find it very easy to not grieve over paid-for-but-unused work.

Applies to many things, Stephen King on writing: "You have to be willing to kill your darlings."

I get paid to write code, I couldn't care less if it's deployed or not.

If they pay me to write it, and it doesn't get used, that's their waste of money / time, not mine.

As long as the code is versioned you don't completely kill your checked in darlings.