The biggest lesson from the 100 billion people who are no longer alive is that they tried everything we’re trying today. They swung from optimism to pessimism at the worst times. They battled unsuccessfully against reversion to the mean. They learned that popular things seem safe because so many people are involved, but they’re most dangerous because they’re most competitive.

Same stuff that guides today, and will guide tomorrow.

There’s as much to learn about your field from other fields than there is within your field. Once you see the roots shared by most fields you realize there’s a sink of information you’ve been ignoring.

Communication is important. Many doctors who struggle to communicate effectively with their patients results in patients who don’t stick with treatment plans and are resistant to lifestyle change.

There are millions of these dots to connect.

I have seen investors justify strategies and sales techniques they fiercely argued against at previous employers, coming around the moment their career depended on it. These are good, honest people. But self-interest is a freight train of persuasion. When you accept how powerful it is you become more skeptical of promotion, and more empathetic to those doing the promoting.

It’s usually viewed as a conservative hedge, used by those who don’t want to take much risk. But when used appropriately it’s the opposite. Room for error lets you stick around long enough to let the odds of benefiting from a low-probability outcome fall in your favor.

• Learn faster than your competition.

• Empathize with customers more than your competition.

• Communicate more effectively than your competition.

• Be willing to fail more than your competition.

• Wait longer than your competition.

Everything else – intelligence, design, insight – gets smashed to pieces by competitors who are almost certainly as smart as you.

People believe what they’ve seen happen exponentially more than what they read about has happened to other people, if they read about other people at all. We’re all biased to our own personal history. Everyone.

[Y]ou both understand something that people who haven’t experienced those things never will, but you’ll also likely overestimate the prevalence of those things happening again, or happening to other people.

Start with the assumption that everyone is innocently out of touch and you’ll be more likely to explore what’s going on through multiple points of view, instead of cramming what’s going on into the framework of your own experiences. [I]t’s the only way to get closer to figuring out why people behave like they do.