Introduction

Most people tell themselves a comforting story: "I chose this."

I chose my career. I chose where I live. I chose my beliefs. I chose my routines. I chose my friends. I chose how I spend my attention.

But if you zoom out, most of those "choices" are downstream of something quieter and more powerful: defaults.

A default is not a preference. It is not a decision. It is what happens when you don't decide—when attention runs out, when information is incomplete, when the cost of evaluation is too high, or when the environment quietly chooses for you.

Defaults are the hidden governors of outcomes:

• They determine which doors you even notice.
• They shape which people you meet and which opportunities you encounter.
• They compress possibility spaces without announcing that anything has been lost.

This matters because modern life is increasingly default-driven. Systems are optimized to reduce friction—often by removing choice. That can be beneficial, but it also means the most consequential decisions in your life can be made without you ever noticing a decision was made.

This book treats default as a primary explanatory primitive across domains:

• In life: defaults become destiny.
• In products: defaults become behavior.
• In markets: defaults become power.
• In discovery: defaults determine which unknown unknowns you are ever exposed to.

The goal is not to glorify "choice." The goal is to make defaults legible.