From Twitter

Police Officer: What are you doing in Japan?
American: Mind your own business.*
PO: Ya know my job?
A: Crossing guard?
PO: Nope. Try again.
A: Meter Maid?
PO: No!
A: Tax man!
PO: Wrong.
A: Security guard?
PO (Looks at sky): "..."

*Means:
a. Go to work
b. Care for your concerns

Answer And Explanation:
The answer is b., Care for your concerns. We say this ( "Mind your own business") when it seems someone is looking into and minding (watching over/involving him or herself in) our affairs unsolicited (unwanted, not asked for). For better and more thorough explanations than this, come to class at Shinjuku English Institute. Social media cannot replace a good teacher in the flesh!