A woman becomes a mother with a whole lot of hopes and rosy dreams. Most of those dreams revolve around the tiny bundle of joy you will be holding and feeding and playing with.
Most new mothers are ill-prepared for the time when the tiny bundle of joy grows up, becomes a teen ager, and start having an identity of her own, opinions of her own, which are the polar opposite of yours. Still worse, they do not seem to think that your opinion matters, and that what you think is not applicable to their world. The worst part of all this is that there is absolutely nothing a mother can do, and it drives you nuts.