This essay is spot on. I'm a big believer in having "fuck that" money. When I have less than that, I feel trapped for obvious reasons. When I have more than that, then the money itself brings additional headaches and pains that also grind me down.
Agree, though it's kind of an odd way to express the idea. Looking at it another way, make sure your expenses always remain so low that you can simply walk away from any job. That's the only way to remain free.