It was less complicated when it was all on paper and everything matched up perfectly. The real world is never quite so neat and tidy.
Every day, couples all over the world put lots of effort into planning their their wedding day without putting any thought into what is going to happen once the big day is over. Then, over the months and years a marriage can slowly go downhill and you cannot work out why. Before you know it, you find yourself in a situation of trying to save your marriage.