Important question. In the early stages I think you must be:
...willing to sacrifice almost everything. Can you?
...willling to work 60+ hrs per week. Are you?
...willing to make little money. Can you sustain yourself?
...willing to sweat through sleepless, worried nights. Want to?
...willing to go places completely different than what you expected when you started out. Can you?
Can you? Can you? Can you? Most can't. Or won't. It's a mystery to me which applies.