Unrealistic expectations
As part of my work, I have meetings and conversations with couples prior to their weddings. We don't just plan the ceremony. We also use an inventory which purports to measure the couple's "Strengths" and "Growth Areas." The inventory gives us many possibilities for conversations that we can have about their relationship.
Some of the possible strengths (or 'growth areas') named are: Communication, Conflict Resolution, Relationship Roles, Family and Friends, Spiritual Beliefs, Children and Parenting.
You get the idea.