If you're not enjoying what you're doing, and you're sacrificing so much to do it, then there'd better be some pretty big pay-off at the other end. Pretty big gamble to be taking essentially on faith otherwise.
Aaah, but that's just it - I do enjoy what I'm doing. I'll be disappointed if there isn't a big payoff at the end, but I enjoy the process of creating, building, learning, growing and discovery. Working on this startup has taught me so much and taken me in so many interesting directions...
I guess you could say I'm an adherent of the mindset that "startups are the new graduate school". I love learning new stuff and forcing myself to learn what I need to know to do this startup is a great experience in many ways.
But like everything in life, there are always tradeoffs.