When we say “mind your own business,” it means that a person should not interfere with things that do not concern them. It’s equivalent to saying, “don’t meddle” or “keep to your affairs.”
Here are two examples in sentences:
Example 1:
When his neighbor started asking too many personal questions, John said, “please mind your own business“.
Example 2:
Mary didn’t like when people gave her unsolicited advice, so she often told them to mind their own business.
Here are examples in conversation:
Example 3:
Alex: Why were you talking to my boss?
Ben: Alex, you need to mind your own business. It has nothing to do with you.
Example 4:
Emily: Why don’t you start a family? You’re not getting any younger.
Lisa: Emily, I appreciate your concern, but you should mind your own business.
So, when someone says “mind your own business”, it’s a somewhat direct way of asking someone not to interfere with private matters or situations that don’t concern them.