More accurately, what you need is F You money so you can tinker with projects. He started out describing his company as a nightmare, but now that he's loaded he doesn't have to do anything he doesn't want to.
As a founder who makes a modest living from his site, I can say that you don't need to be rich or have "F You" money to enjoy the experience that Derek writes about. You just need to have enough of a reputation that people will be interested in giving your new projects a chance.
It's such a great experience to come up with an idea, integrate it into your site a few days later, and instantly have thousands of people using it, giving feedback about how great it is or how much it sucks. Watching your ideas instantly take off or dud.
When you work for a company, you may have a very large potential audience, but you may not be allowed to try out some of your best ideas (and even if you are permitted to work on them, they may never launch to the public). Likewise, if you are an individual working on ideas in your spare time and not giving them your full attention, you may never gain enough of an audience to know if your ideas are good.
Really, "your own company is one of the best playgrounds of all" sums it up perfectly.
