I suppose it's the rampant teaching that discipline starts at birth and you have to control every thing and "keep your baby in line" or your baby will grow to be a child who rules you.
That's a lie, well the second part is.
But yes, discipline does start at birth,
Yet you brought me out of the womb; you made me trust in you even at my mother's breast(Psalm 22:9)
We can't learn every thing we need for life unless we trust. We can't grow up confident and able to stand up in the world and what it throws at us unless we feel secure.
Teaching a baby that you are always there is discpline.