It isn't that hard, it is especially not that hard if you approach it like he did and grow very slowly and keep your costs down. I did the same thing with my best friend years ago, starting off while still having a job, then making a leap when things were slightly vetted.
Best decision of my life. I've travelled the world, set my own schedules, always worked on what I wanted to work on and had a far more interesting set of challenges than I would have staying coding at another startup.
The key is not to aim for the moon, aim to pay the bills. We reduced our expenses to $5k (pre tax) a month, then set that as our goal our first year. It was achievable, but more importantly we eventually grew to making far, far more than that. But I've still always kept my expenses low because I've always wanted the freedom to do what I wanted.
I'm now in Africa, doing a startup here because it is new and exciting and satisfies my need to do good. Never would have been here if I had stayed at the day job.
(no offense intended to patio11:)
Although, the number of people that I know that learned Japanese in America is, like, two. I would say that makes him exceptional in that regard.
See this blog post for the whole story of how I got here:
I should mention I first saw txtGate here on HN because the developer is a member. More of a proof of concept than anything else, but a great idea.