Q. What quality or skill is the most critical to success as an entrepreneur?
It helps to be dumb and scared.
Tenacity is key because it keeps you going during tough times, but it must be tempered because sometimes you need to back down or walk away.
Never give up. You need to be too dumb to quit.
You need to have the willingness to go deeply into debt.
I can only speak for myself. I lack the fear gene. That's what's made entrepreneurship possible for me.