There are a great many couples that met when they were just small children. They grew up in the same neighborhood, and often attended school together. These people were friends or enemies, depending on their age. After a while, they became friends again and began dating. For those that married as teenagers, their relationship never ended. They went on to find a home, have children and settled down into their married life.
There are many advantages to being married to a childhood sweetheart. There is no need to go through the awkwardness of getting to know a stranger. Growing up in the same neighborhood and school system gives two people the advantage of compatibility. This is great for both people unless one decides they have missed out in life. Sometimes one, or both, of the people in this type of relationship will feel they did not have the freedom to pursue their dreams.