Jeff Aronson warns that prolonged success breeds dangerous overconfidence. When an investor is on a hot streak and feels they can do no wrong, their perception of risk becomes warped. This psychological shift, where they think "I must be good," is precisely when underlying risk is escalating, not diminishing.

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.

There's a surprising disconnect between the perceived brilliance of individual investors at large, well-known private equity firms and their actual net-to-LP returns, which are often no better than the market median. This violates the assumption that top talent automatically generates outlier results.

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.

Buffett emphasizes 'controlled greed.' His equally smart partner, Rick Guerin, was impatient and used margin loans. When the market fell nearly 70% in 1973-74, he was forced to sell his Berkshire shares back to Buffett for a pittance, missing out on generational wealth.

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.

Widespread credit is the common accelerant in major financial crashes, from 1929's margin loans to 2008's subprime mortgages. This same leverage that fuels rapid growth is also the "match that lights the fire" for catastrophic downturns, with today's AI ecosystem showing similar signs.

Quoting G.K. Chesterton, Antti Ilmanen highlights that markets are "nearly reasonable, but not quite." This creates a trap for purely logical investors, as the market's perceived precision is obvious, but its underlying randomness is hidden. This underscores the need for deep humility when forecasting financial markets.

Warren Buffett's early partner, Rick Gurren, was as skilled as Buffett and Munger but wanted to get rich faster. He used leverage, got wiped out in a market downturn, and missed decades of compounding. This illustrates that patience and temperament are more critical components of long-term success than raw investing intellect.