I was chatting with a kid interested in entrepreneurship recently. He wants to start some sort of business and asked me where to begin. That’s a broad question, so I shared my story.

When I was a teenager, I was obsessed with fixing up cars and spent tons of time learning about it. What are the best parts? Who makes them? How do you buy them? How are they installed? I was more knowledgeable than most people. My friends ended up paying me to help them fix up their cars. And that morphed into a large business years later.

I ended by advising him to find a problem he’s obsessed with and keep feeding his obsession. Eventually, the obsession will lead to figuring out how to solve the problem. Others will think his obsession is odd at first. But once he masters the problem and solves it, they’ll think he’s a genius. They may even end up being his customers.