From what I gathered, "not your Onions" simply means, "mind your business".
It is quite the interpretation because I never really thought of it this way.
I know the use of the expression for onions is the, "I know my onions", meaning intelligent in your own way".
The conversation would not be well understood except both parties have adequate knowledge of the phrase. Take for instance, I cannot say this to someone who does not understand what I mean. Their first assumption is to the onions, as many others will guess too.
However, we learn everyday.
And learning this is an additional knowledge.
You can also participate by clicking here
