I recently came across a story that shows how a single contract can completely change your life—and how important it is to understand the terms before signing.

It all started in 1987. Steve Rothstein, then 21 years old, did something most would consider crazy: he paid $250,000 for a special pass with American Airlines. Not for a trip, but for the right to fly for free for his entire life. An additional $150,000 for a pass for a companion. Sounds absurd? It probably was—but it was completely legal.

American Airlines called this the AAirpass and offered it to only a small group. In 1994, they realized what a mistake that was and canceled the program. But here’s where it gets interesting: Steve Rothstein and about 27 other holders could simply keep flying. The contract was the contract.

What happened next is almost unbelievable. This man flew practically every day for over 35 years. 10,000 flights. 30 million miles. Some days he booked two flights back-to-back. Sometimes just for lunch in another state and back the same day. Sometimes he helped homeless people visit their families. Sometimes he just booked seats but didn’t show up.

American Airlines was not happy. They lost over $21 million because of Steve Rothstein. In 2008, they tried to stop him in court and claimed abuse. But the U.S. has a strict rule: a contract is a contract. Steve Rothstein won the case.

Today, fewer than 20 people worldwide have such a pass. Steve Rothstein is not just a frequent flyer—he’s a living symbol that sometimes a small clause can open all the doors of the world for you. A lesson about contracts, promises, and how important it is to understand what you sign.