Scientists who study the mechanics of curiosity are finding that it is, at its core, a kind of probability algorithm—our brain’s continuous calculation of which path or action is likely to gain us the most knowledge in the least amount of time. Like the links on a Wikipedia page, curiosity builds upon itself, every question leading to the next. And as with a journey down the Wikipedia wormhole, where you start dictates where you might end up.

Curiosity is less about what you don’t know than about what you already do.

The old view is that curiosity and boredom are opposite ends of the same continuum.

The new view: bored is not to curious as hungry is to full or thirsty is slaked. Rather, boredom is a signal that you’re not making good use of a part of the brain. And the...