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.

While technical analysis has its place, true long-term success in markets is overwhelmingly determined by one's inner journey. Mastering self-awareness, emotional discipline, and psychological biases is far more crucial than mastering complex financial models.

True investment prowess isn't complex strategies; it's emotional discipline. Citing Napoleon, the ability to simply do the average thing—like not panic selling—when everyone else is losing their mind is what defines top-tier performance. Behavioral fortitude during a crisis is the ultimate financial advantage.

Doing well financially isn't about complex strategies; it's about survival. The ability to endure market downturns, career setbacks, and unexpected events without being wiped out is the prerequisite for long-term compounding. As the founder of Four Seasons said, "excellence is the capacity to take pain."

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.

Acknowledging he was susceptible to self-sabotage by trying to be overly clever, Keynes evolved a systematic process. By investing in fewer positions, holding them longer, and focusing on clear criteria, he deliberately reduced opportunities to act on his worst impulses, mirroring Buffett's "one-foot hurdle" approach.

Even one of history's most brilliant minds, Isaac Newton, fell victim to financial mania. He invested in the South Sea Company, sold for a profit, but then FOMO drove him to reinvest at the peak, leading to massive losses. This demonstrates that emotional discipline, not just intelligence, is crucial for investing success.

Success in investing relies on controlling emotional urges, like herd mentality, rather than high intelligence. Buffett's famous quote and his actions during the dot-com bubble illustrate that emotional discipline is the key differentiator for great investors.

The fathers of physics and biology both lost their fortunes in financial speculation—Newton in the South Sea Bubble and Darwin in railways. This demonstrates that intellectual brilliance in one domain does not translate to financial markets, which are governed by psychology and mercurial forces.