Monello is retired military and owns property that provides him with additional income. I'm still working, just from the road now. Even if your job doesn't give you the option of telecommuting, there are unlimited ways you can earn money on the road. Work camping and temping is more popular than I realized when we started this journey.
The RV is our home - we don't have another home we're paying for. No mortgage, no rent, no utilities. That makes a HUGE difference in what we're able to afford. The cost of a monthly stay in a good RV park goes from $500 - $1500, utilities all included, many times including cable TV and almost always including wifi access.
Neither of us has an emotional attachment to a home or location or being near family, and we don't care about our previous nice things. We were both meant for this lifestyle, and it's certainly not for everyone. At first I missed my kitchen and having my own bathroom, but the joy of travel and experiencing new adventures way compensates for that and now I don't miss "home" at all.
The short answer is that you CAN take off and be a free spirit - anyone can. It's what you're willing to give up to get it that prevents most people from hitting the road.
Fear was the biggest hurdle for me - you can ask my friends, I was a freaking basket case worrying about the unknown. But one I wrapped my mind around the "what-ifs", they didn't seem like such a big deal and it was nothing that couldn't be planned for or overcome. And so far we haven't run into anything that was a big issue. Very occasionally I would get bent out of shape at the lack of space, but now I'm used to it.