Congruence
It is less than enjoyable to be on a dance floor that, for the lack of anything more inventive, would be likened to "a can of sardines". If I were to take a hack at being inventive, I would say that people were tessellating in there; but let's not be silly, people don't tessellate.
Oh, but my, it would be enjoyable if people could tessellate. Think of all the amazing things we could build with tessellating people. And police barriers would be so much more effective if they tessellated, instead of linking hands and trying to dam the sea.
Perhaps it is because people do not tessellate, that we find ourselves at odds with each other so often. For you see, if it is in our physical nature to be at eternal conflict with incongruent elbows and knees, then it may well be in our psychological nature to be at eternal conflict with incongruent thoughts and ideas.
Therefore, I conclude that if people tessellated, there would be World Peace. QED.