Why do people believe they have to mate with other people?

I was asked,

“Are you married yet?”

And I hate it..

Everyone is not the same.

Why do people ask you if you are married? Why do people ask you do you have kids? Why is it assumed that everyone has kids or get married?

Why do people think everyone agrees with mating and child producing?? Why do people think they cannot be alone? Why do people think they cannot be happy alone?

What makes people believe everyone believes in the idea of marriage? Why do people think their only purpose is to get married?