Each person is existing within their own reality, viewing things through their own perceptions, interpreting things from their own experiences. That explains a great deal. It explains why you and your spouse heard entirely different things when having a discussion about the budget. It explains why your kid thinks 'picking up his room' means piling everything in a corner ("I picked it up to move it there"). It explains why your parents thought they did a damn fine job of raising you, but you and your siblings may beg to differ.