Okay fair enough about it not being a perfect analogy.
I think the reason junior devs get them confused is that many junior devs are never taught anything about either in school. But then you just tell the junior dev that they mean different things and in my experience they only need to be told that once.
“Permission” and “persistence” have the same prefix but entirely different semantics. They also occur more commonly in everyday life.
AuthN and AuthZ are similar in in spelling, appear in similar contexts, and are less colloquial, making the distinction a lot less clear.
There’s a reason many junior devs use them interchangeably without knowing better.