Simple pairing is a process of finding things which are alike and putting them together. When this is done successfully there is less of a repelling force, which is a reaction. These pairings can be things as simple as likes, dislikes, size, age, taste, habits and interest. Done properly this could be the source for sustaining relationships for life.
STEEMON
Well, maybe it's easy to overcome difficulties, but hurt to learning find compromis. And compromis needs even when you are very similar.
You are right, with similarities it is easier, and there should be a willingness to move forward, which leans to mutual commitment.