> Ask to someone who learns French, for instance. Rules with too many arbitrary exceptions.
I took French in middle school, and it was always a running joke that the teacher spent the first 5 minutes on the rule, and the next 40 minutes on the exceptions.
I am French and my non-native-French wife often asks me "why do you say this and that".
Either there is a simple rule and well known exceptions we learn at school (she would also know) or we get into the area of "this is what this is, just learn it by heart".
And then suddenly, someday, I discover there is an obscure rule with complicated words that addresses the question.
I took French in middle school, and it was always a running joke that the teacher spent the first 5 minutes on the rule, and the next 40 minutes on the exceptions.