Why is Nami so obsessed with money?

Could you elaborate on the reasons behind Nami's seemingly relentless pursuit of wealth? Is it a personal drive for financial security, or does she have a deeper motivation that fuels her obsession with money? Perhaps she has experienced financial hardship in the past, or she sees money as a means to achieve a specific goal or aspiration. Understanding the root cause of her obsession may provide insight into her motivations and actions.