I love the analogy about lions in the wild. When you are living by your wits, there is a sense of "apprehension" (not sure I would call it fear) but that is where the adrenaline comes from and also the sense of freedom. You are (more or less) in control of your own destiny.
I am a veteran of the tech industry. Started a few companies and consulted for a twenty year period. I haven't had boss (the wife excluded) during the entire time except for a stint with Shell Oil out of school. Just recently graduated from law school (went back as an "old man") and am in the process of launching a "digital law practice" that feels in many ways like a tech startup. We are doing it completing "on the cloud" with virtual offices in a couple of states.It has gotten a lot easier (still not "easy") to do!