In Wind, Sand and Stars, Antoine de Saint-Exupéry writes,
“Love does not consist of gazing at each other, but in looking outward together in the same direction.”
It’s an idea that’s echoed in Shel Silverstein’s The Missing Piece Meets the Big O, an allegory of love masquerading as a children’s book. A wedge-shaped character, the eponymous missing piece, is “waiting for someone to come along and take it somewhere”.
After several unsuitable candidates pass by, he eventually finds a circle with a hole that he fits perfectly, and for a time the two roll on together. But the piece continues to grow, whereas the circle does not, and before long the two no longer fit. Brain Pickings’ Maria Popova makes the obvious inference:
"And just like in any relationship where one partner grows and the other remains static, things end in disappointment — and then they just end. The static circle moves along, looking for a piece that won’t grow."
Then one day a shape rolls by that has no pieces missing, the Big O.
“I think you are the one I have been waiting for,” said the missing piece. “Maybe I am your missing piece.”
“But I am not missing a piece,” said the Big O. “There is no place you would fit.”
“That is too bad,” said the missing piece. “I was hoping that perhaps I could roll with you…”
“You cannot roll with me,” said the Big O, “but perhaps you can roll by yourself.”
At first, the missing piece is baffled. He has corners and flat edges and won't roll well at all. But the Big O points out that corners can be rounded off ("another elegant metaphor for the self-refinement necessary in our personal growth" notes Popova), and so the missing piece painfully begins to haul himself end over end. Gradually his corners do start to round off; indeed, he becomes rounder and rounder, until finally he starts "rolling, like it always dreamt of doing with the aid of another, only all by itself".
It's then that the Big O returns, and at the end of the book the two are seen rolling in the same direction, side by side.
This idea of two independent, self-sufficient people moving through life in the same direction is echoed by Alexander Seinfeld in an answer to the question, “What is the purpose of marriage?”, on Quora:
“Marriage is a commitment that two people make in order to pursue their life goals together.
This definition sheds light on why marriages succeed or fail. To the extent that the two (a) share the same life goals and (b) remain focused on those mutual goals, they have a high chance of a long-term stable happy marriage. The opposite is also true.
One of the big mistakes couples get when they get married is failing as individuals to clarify their life goals. Sometimes the only life goal they have in common is having and raising children. Guess what happens in such marriages once the kids are grown?”
In this view, marriage is more durable when it’s about cementing Saint-Exupéry’s idea of love rather than the traditional romantic ideal. Far easier to accommodate separate rates of growth when you’re rolling side by side than when you’re snugly interlocked.