To achieve true freedom, one should calculate the "last dollar" they will ever need to spend. Once this number is reached, decision-making can shift away from financial maximization. This framework helps entrepreneurs avoid trading their best hours for "bad dollars"—money that provides zero additional life utility.

Purely rational choices, like never paying off a low-interest mortgage, ignore the powerful emotional benefits of security. Housel argues for being "reasonable"—making choices that help you sleep at night and align with your personal psychology, even if they aren't optimal on a spreadsheet.

Contrary to the economic theory that more choice is always better, people sometimes prefer fewer options. Removing a tempting choice, like a bowl of cashews before dinner, can lead to better outcomes by acting as a pre-commitment device, which helps overcome a lack of self-control.

Phenomena like bank runs or speculative bubbles are often rational responses to perceived common knowledge. People act not on an asset's fundamental value, but on their prediction of how others will act, who are in turn predicting others' actions. This creates self-fulfilling prophecies.

Traditional economics often repels people with complex math. Economist Kate Raworth intentionally used the simple, non-threatening metaphor of a "donut" for her alternative economic model. This disarmed common fears around the subject and encouraged broader, more accessible engagement.

Seemingly irrational financial behaviors, like extreme frugality, often stem from subconscious emotional wounds or innate personality traits rather than conscious logic. With up to 90% of brain function being non-conscious, we often can't explain our own financial motivations without deep introspection, as they are shaped by past experiences we don't consciously process.

Contrary to popular belief, economists don't assume perfect rationality because they think people are flawless calculators. It's a simplifying assumption that makes models mathematically tractable. The goal is often to establish a theoretical benchmark, not to accurately describe psychological reality.

Milton Friedman's 'as if' defense of rational models—that people act 'as if' they are experts—is flawed. Predicting the behavior of an average golfer by modeling Tiger Woods is bound to fail. Models must account for the behavior of regular people, not just theoretical, hyper-rational experts.

Maximizing profits in a crisis, such as a hardware store hiking shovel prices during a blizzard, ignores the powerful economic force of fairness. While rational by traditional models, such actions cause public outrage that can inflict far more long-term brand damage than the short-term profits are worth.