Sometimes we always think the kid can't understand our conversation between the adults. In fact, the kid is very smart and can understand the main meaning in his own mind.
In my memory, my son could remember our talks between my wife and me. And to our surprise he can give us some advice. We should pay more attention to our behavior. We had better give my son a better impression. My son often imitates our words and watches our attitudes dealing with things.
I have to improve my bad habbits and show my best aspects to my son. If there is a better family environment, the kid can grow up better.