Why do people stay in relationship where both aren't on the same page?

For instance if someone wants kids and the other doesn't, then they need to break-up. That is something that can't be compromised since they both want something totally different from one another.

Yet several people still stay in those relationships. Why? It's already a dead-end right there and they're wasting each other's time.

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+1 y
No amount of ''but we're having a good time, I love his/her company'' is going to solve huge differences like that.
Why do people stay in relationship where both aren't on the same page?
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