Choosing the "wrong mate" for themselves. - This happens when a person has yet to figure out who (they) are, what they want and need in a mate for life BEFORE selecting a mate. It's the equivalent of going shopping without a list! This type of person is likely to allow "happenstance" and "impulsive connections" dictate their relationship choices. In the end they hope their mate will "change" or become the person they really want.
The goal is to find someone who shares your same values, wants the same things for the marriage you do, naturally agrees with you on how to obtain those things, and last but not least have a mutual depth of love and desire for one another. Like attracts like in the long run.
Opposites attract divorce attorneys!
Getting married for the "wrong reasons". This happens for example when one has set an "age goal" to be married by, there is an unplanned pregnancy, an ultimatum was given, all of their friends are married, simply just grew tired of being single, someone joined the military and is about to depart....etc
A marriage based around circumstances is likely to fail.
Having "unrealistic expectations" of what marriage will be like. Most days will NOT be filled with "sunshine and rainbows". Many people feel something similar to (post holiday blues). They've been dreaming about their wedding and living a life of "happily ever after" with someone and after a year or two they discover there really isn't anything "magical" about being married.
In fact if anything people tend be more likely to "RELAX" in a relationship after saying "I do". It's like having a new job and doing your best work while you are on probation but once you know "the jobs is yours" you start to slack off. People do this in marriage.
They STOP doing many of the things that won their mate's heart! It's almost a cliché to hear someone say: "He/she is not the same person I fell in love with." We're either growing together or growing apart.
Marriage is garden that has to be nurtured and tended to everyday.
There are only two ways to experience joy and peace of mind in a relationship: We either get what we want or we learn to be happy with what we have. The choice is up to us!