There is one thing that you can trust everybody to do, and that is to put his interest above yours.

Everyone's Interest Comes First

We like to think people are fundamentally good or that they'll naturally consider us. But Friedman points at something simpler and more useful: everyone—including you—is wired to prioritize their own interests first. This isn't cynicism; it's just how incentives work. Your boss won't sacrifice the quarterly numbers for your wellbeing. Your friend won't pass up the job opportunity to protect your feelings. Your family member won't give up their comfort for yours without some reason to.

The surprising part is that recognizing this doesn't make you paranoid; it actually makes you smarter. When you stop expecting people to magically care about your interests as much as their own, you can design better systems. You ask for things explicitly instead of hoping hints will work. You build contracts instead of relying on vibes. You create situations where people's self-interest and yours actually overlap, rather than clash. A good manager doesn't hope employees will work hard out of loyalty; they structure compensation so effort pays off. A good friend doesn't expect you to read their mind; they tells you what they need.

The world runs better when we stop being disappointed by human nature and start working with it.