"It is a wise father who knows his own child."
-William Shakespeare (from The Merchant of Venice, Act II, sc 2)
Parenting a child is such an ordinary and surreal experience. You realize you are your parents, whether that is a good thing or a bad thing. You realize how incredibly smart and capable your parents were/are. You realize that your parents must have also had moments of doubt, wondering if they really knew what the hell they were doing trying to raise a child into a responsible adult. And then you realize that being a parent is such an ordinary thing. An ordinary thing that never feels anything less than extraordinary.
Once you get past the baby stage, you realize that this tiny human is actually another person. Someone with dreams and desires and fears and passions. It's disconcerting, they've been so predictable until now. Crawling, eating, walking, talking. Oh the talking. The joy and bane of my existence is the talking. The point is, once they start talking, they can tell you their internal monologue, and you realize how much you have missed. You assumed that they thought the same things you did, because they are your mirror, your reflection, with a doubly familiar face and your words and actions. Until one day, they say something new. Something you never thought or said or did. And you realize you will only ever know them as well as you can know another person.