> was taught that the code should "document itself" > comments were an anti-pattern to writing good code

I've been programming in one form or another since I was 8 years old (around 38 years) and this was obviously incorrect to me back then, even though I wasn't sharing my work with anyone else, and hadn't heard this concept.

Years later I was astounded to move into a "modern" dev environment where people (developers, devops) parroted this line regularly. As you say it's nice in principle, but in reality relying on it proves to be impractical.