Comment by blacksoil

Thanks for sharing this! I think your explanation really hits the nail. Reminds me of what Pope John Paul II said on a similar topic in a husband-and-wife context (book title: "Love and Responsibility"). He said that all relationship is build on "common ground" (i.e. school project, work project, etc) and this is one of the reasons why the Catholic church mandates a couple to have the willingness and openness to have children as a prerequisite to get married in the church. Children are one of the "common ground" that glue the relationship between the husband and the wife.