Relationship being like a piece of blank paper

A quote from someone.

about relationship being like a piece of blank paper. Both of you starts with a clean sheet of paper and initially both of you will be happily writing your story on it. Over time, one may be tired and write less and the other party has to put in extra effort and fill in the space. Sometimes, it might be the other way round and one party have to compromise or give in or put more effort to ensure the words keep flowing. If either party chooses to stop writing or chooses to write on another piece of paper, the story just can't go on. It's as simple as that.