No necessarily. It depends on a person's yearly expenses. If, for example, she was able to save 10 years salery in 20 years, it would mean that she consumes onl

No necessarily. It depends on a person's yearly expenses. If, for example, she was able to save 10 years salery in 20 years, it would mean that she consumes only 5 % of the total savings per year. This sounds quite sustainable, because you need only to achieve a 5 % return on investment (after inflation) on the savings to live just from these returns not touching the savings at all.