What we know.

 Most of what we know about the world, we learn from other people. Therefore, our ability to understand the world depends on our ability to understand people.

We live in a world full of people who need and want things. They will ascribe value to us according to our ability to provide for their wants and needs.

Each of us will die, and others will live on after us. Whatever we may believe about the afterlife, this is the only empirical truth we know about life and death in this world.

People are complicated. Assessing and navigating our position in the social universe is the most difficult, and most important, mental task that we perform in life.