I was watching two kids play a simple card game. One, about ten years old, was confident and competitive. The other was a younger sibling. They were playing “high card”—each simply flips a card, and the higher one wins. After a few rounds, the older kid grinned and said, “I always win and you always lose. You’re unlucky.” The younger one just shrugged. “I know I always lose,” she said, as if it were simply a fact.

Imagine a time in prehistory when humans lived as cave-dwelling hunter-gatherers, surrounded only by nature and limited to a few primitive tools. One day, a distant ancestor is out foraging when it starts to rain. Tired of being constantly soaked, he glances at the fallen branches and broad leaves—and suddenly has an aha moment:

Imagine you're a Catholic sitting in a church pew on Sunday morning. It's a plausible assumption that everyone attending Mass with you shares your faith. You're all Catholics, part of the same religious group. But in reality, the person next to you may not believe exactly what you do.

Picture a game of Plinko — the kind where you drop a chip down a board of pegs, and it bounces unpredictably into a winning slot. Now imagine the chip is alive — and gets interviewed after the game.

Every day, the same mailman delivers your mail, dressed exactly as you’d expect. One day, though, you glance out the window — and there he is, in a full clown costume, nonchalantly delivering the mail as usual. A bit perplexed, you mention it to your neighbor George later that day. “Did you catch Ed the mailman wearing a clown suit earlier?” “Yeah,” he says. “Pretty weird, right? Any idea why?” But he had no idea either.