Asymmetry in a positive sense means you benefit more from random events than you lose (or lose less than your neighbor), positioning yourself like an option where upside is larger than downside, allowing you to do very well in the long run provided you survive.

Trial and error (tinkering) has a really positive asymmetry: the upside is potentially unlimited (discovering something genuinely good) while the downside is bounded (you simply don't lock in the gain and move on), making it superior to top-down design.

If you want to create the best pizza (the Santa Monica Flying Pizza), the trial-and-error approach is to rent a bus, find well-dressed overweight people (as a proxy for people who understand good food), have them iteratively add ingredients, lock in gains when something tastes good, and incur minimal loss when something doesn't work.

In trial-and-error, the downside is minimal (you simply don't adopt something that doesn't work) while the upside is maximal (discovering something genuinely good), but a chemist's top-down approach trades off limited upside for potential massive downside if the theory-based approach fails.

Negative asymmetry occurs when you transfer the upside to yourself while transferring the downside to someone else (typically the anonymous taxpayer), and this is a bad asymmetry.

The only true measure of success is looking at yourself in the mirror in the evening and not disappointing the person you were at 18, before people get corrupted by life, with only that person as judge—not reputation, wealth, standing, or decorations.

Taleb cured his back injury sustained while writing 'Antifragile' seven years ago through deadlifting, which led him to discover the value of intense heavy weightlifting for human bone health and physiology.

Secret societies operate by the rule 'wo donor'—you are as good as what you do for other members—which demonstrates that virtue is inseparable from courage and risk-taking for others' sake.

All other definitions of success besides self-respect are modern constructions—fragile modern constructions that contrast with how ancient societies (like the Greeks) defined success as having heroic deaths.

In a less martial society, success can be adapted as having taken a heroic route for the benefit of the collective, whether narrowly or broadly defined, provided the benefit is for someone else rather than oneself.

You should treat the doorman with more respect than the boss, because the boss can fall but the doorman cannot—meaning vulnerability should be met with greater respect.

Success requires the absence of fragility, and external success—wealth, status, power—paradoxically increases fragility and insecurity in most people who achieve it.

The worst cases are former officials with impressive CVs who become addicted to the attention of servile bureaucrats, then experience devastating loss of identity when they leave office—like having one's house emptied of all furniture.

Self-respect, by contrast with external success markers, is robust—it allows people to wake up happy and go to bed happy, as exemplified by village citizens proud of their local standing or Russian mathematicians proud of modest income and work appreciated by few.

Some wealthy people are robust and self-respecting, but you don't hear about them because they aren't socialized—they live ordinary lives, don't follow news, and don't seek visibility, which is why only the fragile wealthy are visible.

Reading last year's newspaper is an exercise that convinces you not to follow news, because you realize how irrelevant yesterday's news is today.

Taleb walked out of a Bloomberg radio interview when interviewers were saying nonsense, and people told him he'd never get Bloomberg coverage again, but two years later Bloomberg ran a cover story on him—proving the value of integrity.

If something is boring, avoid it—with the only exceptions being taxes and visits to your mother-in-law.

Hammurabi's code was not about eye-for-eye revenge or balance, but rather the principle that you cannot walk away from risks you've created for others—you must be a bearer of the risks you generate.

A civilized society cannot exist unless those who create risks are also bearers of the risks they create.