JMO--- an idealist would think that people live within their means. A realist would say, this is Often NOT the case. A lot of friends I know that live on LI are living way beyond their means....and not even living "richly" A ton of credit card debt, equity lines, etc....just making minimum payments.
A simple example is a Disney Vacation. You can stay at a deluxe resort and spend 10k for the week, or you can still have a nice Disney vacation staying at a more moderate hotel, more moderate food plans, etc... Etc.... But some people will spend the extra money and upgrade the hotel or whatever even though they can't afford it. Or drive an expensive car, or whatever. Just some examples.
And even without big spending.....a kids travel team, or even a kid doing a dance competition can run 5k for the year. It All adds up.