2:30am on a Saturday morning, several years ago:

I was going to school for computer science, and while I was good at it, I didn't particularly have a passion for it. "Programming? Do I really want to write code all day? Sure, I'm good at it, and sure I'll be well paid for it, but the thought of doing it for a living is not exciting."

And then I realized what I was doing, which was watching a seminar on SELinux on YouTube at 2:30 in the morning instead of sleeping next to my beautiful wife, because I was going to figure out MLS/MCS if it killed me. "Wait a second... I spend all of my free time learning about new technologies and being completely paranoid about securing them. I've spent thousands upon thousands of hours working hands on with these technologies, and I have a dozen virtual private servers in various locations around the world, all configured as VPN endpoints so I can be extra-paranoid about hiding my traffic origin. I think I'm obsessed with security, and I like it."

"Maybe I should get someone to pay me to be obsessed with security? That sounds like a good idea. I'll call about changing my major tomorrow. The companies that hire me will never know they're actually paying me to have fun. It's win-win!"

Today:

Penetration tester. Ethical hacker. Information security adjustable wrench.