Yeah right. Because smart people can always control the circumstances of their life like an illness, elder care, affordable housing, change in market conditions, etc.
I try to live by that principle but it's really difficult to actually do it, mostly because of costs related to real estate/housing, and seeing how housing is a big share of almost anyone's salaries (either through mortgages or rents) in the end it gets out of your control.
What I'm saying is that is difficult to live "bellow my means" when it comes to, well, living, which means having a roof on top of my head. I don't want anything fancy, just a safe enough area, decent amount of space and decent amount of transportation options. I'm of course willing to pay for all that, the problem is that there are people who are willing to pay even more, which leaves me with two options: either compete against those other people, which, like I said, makes the "live bellow my means" moot, or, the second option, to compromise on my housing/living arrangements (choosing to live in a less safe area, giving up on access to public transportation, choosing a studio apartment instead of a one-bedroom thing), which is less than ideal (because housing is a basic thing in one's life).