Some of the posters on here don't quite grasp where you are at.
So long as you are very active in life, productive and seeking to better yourself I don't see how this would be an issue. I'm going to assume that you staying home has allowed you to do other things with the money you'd otherwise be using for rent. In a situation like the one you are in, you should be saving up and investing as much as you can, hell I'd go as far to say that you should be working a bit more just to take advantage of this. You are still relatively young and so long as you are doing some of what I mentioned you are in a good spot.
With that said, you should consider yourself thankful that you have the living/financial situation you are currently in. Imagine being a guy in your mid to early twenties just out of college and into his career but yet having student loans, rent.....then a car payment, basic living essentials. It would literally be impossible to get ahead and you'd be forever stuck in that rat race. Now imagine being in this predicament and having to commute, possibly a couple hours or more per day, to some job you had little interest in.
On a side note, I would seriously consider moving to a new area, this would be good for personal development but also financially. There are some pretty major metro areas that have a very low cost of living (AZ, TX, etc.). I think that would be a better investment of your time and money than buying some RV.