Somebody blamed this comment on LLMs, and maybe/probably it is, but I think the first sentence is spot-on so I thought it was worth replying to.

Dealing with the corner cases ends up teaching you a lot about a language and for an ancient language like the shell, dealing with the corner cases also takes you through the thinking process of the original authors and the constraints they were subject to. I found myself in this situation while writing EndBASIC and wrote an article with the surprises I encountered, because I found the journey fascinating: https://www.endbasic.dev/2023/01/endbasic-parsing-difficulti...