Unless you burn your bridges behind you, what's there to prevent you from turning back when things get hard and it feels like you aren't going to succeed?
Well I don't know about you, but it's not exactly easy to get a good job these days. And it's highly unlikely that you're going to be able to go back to your exact same position because they would fill that while you're gone.
I agree that you could potentially go back to working a "regular job" at some point if it doesn't work out for you, but during the transition in either direction, it's certainly not going to be easy.