When you ‘get married’ you are entering into a legal contract. You might be doing a few other things (promising your love to someone, making a deal with a god), but you are most certainly entering into a legally binding contract with another person. There are rights due to and responsibilities incumbent upon people who enter into a marriage contract. Some of these have to do with money, some have to do with children, some have to do with sexual services, and some have to do with other things.
What I find so extremely odd is that even though well over 90% of all people in the USA and Canada get married, almost none of them read the terms of the contract before they sign. (Most people find out about these terms only when they want to break the contract.) Probably because the contract isn’t presented when their signatures are required.
Although this begs the question ‘Is the contract, therefore, still binding?’, the more interesting question is ‘Why isn’t it presented?’