If people want something. Just out of itself to exchange with others. But now money is very important that all have to work in life. To work in exchange for money to survive.
If people want to just remove some of the itself has to share with others, but now money is very important for everyone to use in their work. Working income for life
if they want to just take the Some of their own to exchange for other people, but now they have to use the money more important in my life at work will have to work in exchange for money to sustain life.