It's a human tendency to think of the bad possibility before the good and this also gets applicable in relationships. When we own something precious, we always dread the possibility of loosing it and what can be more precious than relationships? Time, technology and monetary success, has trodden on emotions like trust and commitment giving rise to a disaster called doubt. When we own a thing as precious as relationship, the doubt comes to us with the feeling of love and grows up to become one the biggest relationship problems.