Barcelona Entrepreneurs: What businesses are easy to start, for your situation?

What businesses are easy to start, for your specific situation?

So, you are a knowledge worker, you are a professional, you are a "Corporate Citizen", you are good at your job...

But you want to advance yourself to the next level, start your own business, be your own boss, be the captain of your own ship!

All you can think about is how to escape your corporate job, and become your own boss!!