Cupcake theory

No matter what kind of person we are, we all share one thing in common ... desire to love and foster relationships. But if this is what truly creates happiness, why is it the most complex and the hardest thing to grasp? Even when we are involved in a long term relationship or marriage, we often fall into moments of worry and doubt for our partners and ourselves. Is this normal? How can we resolve this? Why is it that, the most irresistible human desire, the hardest concept to grasp and take control of?