It takes a lot of time, something many young couples are just not willing to invest. They think nothing of jumping in the sack on the first date, then wonder why he or she never calls. DUH! They've gotten what they wanted and they're moving on to the next mark. Taking to time to get to know the other person, to see that person in many different social and family situations gives really good clues as to what life with them would be like.
Unfortunately, many folks think love will conquer all, and it just ain't so. Loving feelings wax and wane over the course of a marriage, and both people need to trust that neither one is going anywhere, so they might as well work on it to make it better.
That's very close to the way my Dad puts it.
Very true.