The Missing Piece is such a great metaphor for the dynamics of relationships that it continues to predict reality beyond even what Silverstein imagined. You've

The Missing Piece is such a great metaphor for the dynamics of relationships that it continues to predict reality beyond even what Silverstein imagined. You've got the wedge and incomplete circle, that when fitting together just right, roll along perfectly. That becomes unstable once one piece changes. Then you've got the end-state: two self-sufficient circles which roll in parallel, just because they choose to. The first two stay together via a strong need, like a dipole-dipole bond between molecules of a solid. The second stay together with a much weaker, Van der Waals force, and are easily separated. It very aptly predicts the rise in divorces in the West once women had more opportunities to be self-sufficient. I won't address if that's good or bad; I just want to compliment Silverstein on a very successful metaphor.