Regularly re-evaluate your investment theses. Stubbornly holding onto an initial belief despite new, contradictory information can lead to significant losses. This framework encourages adaptation by forcing you to re-earn your conviction at regular intervals, preventing belief calcification.

The worst feeling for an investor is not missing a successful deal they didn't understand, but investing against their own judgment in a company that ultimately fails. This emotional cost of violating one's own conviction outweighs the FOMO of passing on a hot deal.

Entrepreneurs often get burned by a failed investment (like a bad ad agency) and become hesitant to invest in that area again. This is a cognitive trap. The first loss was the money spent; the second, more significant loss is the opportunity cost of not trying again with a better strategy.

The "Liking-Loving Tendency" causes investors to identify personally with their holdings. They ignore faults, favor associated things, and distort facts to maintain positive feelings. This emotional attachment leads them to rationalize bad news and hold deteriorating assets for too long, destroying capital.

Scammers don't persuade you to believe new things; they exploit your existing, deeply-held beliefs. The intensity of your commitment to an idea makes you vulnerable, as they gain trust simply by championing what you already hold true. This means everyone is a potential target.

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.

Upfront investments in creative, development, and logistics create immense internal pressure to launch a campaign, even when fatal flaws appear late in the process. This "gravitational force" of sunk costs must be actively resisted to prevent a minor issue from becoming a public failure.

The gap between AI believers and skeptics isn't about who "gets it." It's driven by a psychological need for AI to be a normal, non-threatening technology. People grasp onto any argument that supports this view for their own peace of mind, career stability, or business model, making misinformation demand-driven.

When emotionally invested, even seasoned professionals can ignore their own expertise. The speaker, a researcher, sought validation from biased sources like friends instead of conducting objective market research, proving that personal attachment can override professional discipline.