Whenever theres a situation like Yin and Yang which goes together but are completely opposite to each other or something like Railway tracks which move together in parallels but never meet each other, it can only result in less than average happiness in a relationship between two people. Whereas when situation is like the two Rivers..which after flowing through high terrains and obstacles, meet each other at a confluence and then flow together into the ocean.. sharing the same purpose, it gives a sense of satisfaction and contentment with utmost tranquility in a relationship between two people! Or sometimes a situation can be like two Minds which are parallel poles whose frequency do not quite meet but still they have interconnections like the rungs of a ladder and balance out their separate individuality along with the other persons' ..with a good level of understanding and it surprisingly works! What's more important is to figure out whether your relationship falls into the first category or the second or the third.. The choice is always with us which option to practice!!!