Unlike surgery or engineering, success in finance depends more on behavior than intelligence. A disciplined amateur who controls greed and fear can outperform a PhD from MIT who makes poor behavioral decisions. This highlights that temperament is the most critical variable for long-term financial success.

Trying to beat the market by active trading is a losing game against professionals with vast resources. A simple, automated strategy of consistently investing in diversified ETFs or index funds mitigates risk and leverages long-term market growth without emotional decision-making.

Post-mortems of bad investments reveal the cause is never a calculation error but always a psychological bias or emotional trap. Sequoia catalogs ~40 of these, including failing to separate the emotional 'thrill of the chase' from the clinical, objective assessment required for sound decision-making.

The funding gap isn't just about discrimination. Women, on average, are more risk-averse and often build passion-led businesses that don't fit the hyper-growth VC model. They favor bootstrapping and debt, leading to higher survival rates but fewer billion-dollar 'unicorns,' reframing the definition of entrepreneurial success.

A Wall Street Journal experiment pitted a monkey throwing darts at a stock list against professional traders. Over a ten-year span, the monkey's long-term, passive 'buy-and-hold' strategy won. This demonstrates the power of long-term investing over short-term, active trading.

The emotional drivers of FOMO (buying high) and panic (selling low) make the simplest investment advice nearly impossible to follow. A diversified, 'all-weather' portfolio protects against these predictable human errors better than high-risk concentrated bets.

A study highlighted by Michael Lewis found men systematically overestimate their knowledge, while women underestimate theirs. This cognitive bias is a major risk in investing and leadership. The anecdote of a man confidently miscorrecting "Marie Curie" to "Mariah Carey" perfectly illustrates this dangerous self-assurance.

"Bold" investors chase high returns but risk ruin, yielding great arithmetic but poor geometric returns. "Shy" investors are conservative, surviving longer and compounding steadily, mirroring chipmunks who squawk often but live more seasons. This highlights an evolutionary trade-off between risk and survival.

To combat the urge for constant activity, which often harms returns, investor Stig Brodersen intentionally reviews his portfolio's performance only once a year. This forces a long-term perspective and prevents emotional, short-sighted trading based on market fluctuations.