Why do people get married?

I am curious about the psychology of marriage. Why do people want to get married? I think that people should be able to get married if they want to and to whomever they want, but I am not sure I get why it is important to people to be married. The legal aspect, especially if you have children, is one reason. But I know that is not something most people consider. Why did you get married or why didn’t you?

I am married. It was my husband’s idea to get married. I am committed to our relationship but didn’t need any certificate to say that or the approval of family and friends.