The humdrum existence of many couples is due to their choice of a life with few decisions beyond what their parents experienced, so that is one of the reasons people who grow up together tend to settle down as married couples. They know what to expect out of life, and the emergencies that occur are generally those they learned about as children. It might seem boring to some, but those who choose that lifestyle want some way to know what they are getting into before they take the plunge. The couples where partners are from different places are seeking the adventures of life in a more settled way.
Learning how to conquer their differences is not always the point for these couples, and many of them are more than willing to reach out and embrace the culture of their loved one. They see the challenges of their chosen life as those they are eager to meet. Where a homogeneous couple will know all the holidays they celebrate, there might be vast differences in couples from different lands. Learning the meaning behind them and the rituals is often a welcome undertaking.
Raising children is always a challenge, and the modern world has given couples even more assets and cares. Those who come from different backgrounds have the complexity of sharing their own cultures, but they must also mix them smoothly to keep confusion from burying their meaning. The challenges of parenting children become more complex, but the differences can work to their advantage in some cases.
Building a life with another person can be a challenge in any circumstance, but it could take additional resources for couples of differing backgrounds. They must overcome all the challenges of any married couples, but they will also need to mix in their own special ingredients as they try to find common ground.