There is a theory in Greek literature that when Zeus created humans, he made them complete beings, with two halves together. But when they stopped spending time worshiping him, he got frustrated. He worried that they had to much power together. So his solution was to split them in two. What he did not predict, was that the humans would turn and begin to search for their missing half. They spent all their time attempting to fix what had been broken. The lucky ones who found their other half would feel satisfied, but some were not as fortunate. They gave up. Little did they know, their other half was just around the corner.
People aren’t compatible. And if two people are standing face to face, one is going to be taller.