I agree, and I think that is a great reason to not "escape 9 to 5."
Much to my point about doing it young, if you are unsure, but you are tempted by the siren song of startup fame and fortune. The hype, glamour, fame and fortune is largely the exception and not the rule. The hard work and the hard lessons are much more the norm. The benefits you might receive are earned, and they are paid for in sweat, stress and sleepless nights.
The bottom-line is that it comes down to knowing yourself. You make a great counterpoint to those that are certain working for themselves, or starting a startup is their path.
If you are uncertain, the best way to confirm it is to test yourself, take the risk.