Obligatory XKCD: https://xkcd.com/1053/
While it doesn't apply to shell prompts, there are such things as cultural memory and institutional memory. As a member of a group or society, you are expected to have a certain baseline amount of knowledge of that culture and history.
When I was young, it was considered shameful not to know things. Now the people I work with seem to wear ignorance as a badge of pride. They think that not knowing something means that thing is not worth knowing. As if somehow not knowing something is a good thing.
I mean, I get it in some cases; you don't need to know how things work to use them, but when things go wrong, and they always do, that's when knowing how it works (and not just how to use it) pays off.
Plus, you can articulate questions about things you don't know more effectively.