For many people, having insurance is required, either by the state (for a car) or a bank (for a house). Those who don't fall into these categories often choose

For many people, having insurance is required, either by the state (for a car) or a bank (for a house). Those who don't fall into these categories often choose to self-insure, and self-insurance has the advantage that you derive the benefit of the invested money, rather than the insurance company's stockholders.