curiosity about earning money

why people always curiocity about earning money? did any one can answer best resaon for my answer.
i will put my thought.in no
1: money is that things which help us to survive in this world.
2: beacuse people have no other choise to earn money then other things.
3: this human nature teach us to earn money and to surve.
4: people have lots of deman so money is made itself to exchange there good and materials.