What elfwreck said. Among the limits babies are not born knowing are yours. It's hard to tell them, "You're fed, you're dry, you're warm, now chill out because Mom needs a break," but the alternative is total exhaustion. And twelve years from now you do want to be living with a person who was not taught from infancy that the world was built just for her.

Fathers (like me) can help, but (like me) may need to have the situation spelled out for them.

Oh, and did anyone mention they're not born knowing how to put themselves to sleep? They have to learn it, and the process can be difficult for them and those around them.