We believe that what we possess we don't ultimately own. God is merely entrusting it to us. And one of the conditions of that trust is that we share what we have with those who have less. So if you don't give to people in need you can hardly call yourself a Jew. Even the most unbelieving Jew knows that.
You know if you are kind of rich the best thing is that you don't have to think about money. The best thing you can buy with money is freedom time. I don't know how much I earn a year. I have no idea. I don't know how much I pay in taxes.