People don't like doubt, so they pay money and give up opportunities to avoid it. Entrepreneurship is largely about living with doubt, as is creating just about any sort of art.
If you need reassurance, you're giving up quite a bit to get it.
On the other hand, if you can get in the habit of seeking out uncertainty, you'll have developed a great instinct. Taken from: Whatcha Gonna Do With That Duck? by Seth Godin
For some reason, this passage reminded me of when people ride roller coasters and throw their hands up to intensify the thrill. Their stomachs drop, and a scream comes rolling out of their mouths, but all the while, they know that the car they ride in is designed to hold them inside. They feel safe because they trust in the mechanics. It's still a thrill, but a controlled one.
What if we lived each day like that? Right on the edge of danger and safety. (I know I don't.) What if we threw our hands in the air, and we had faith that we'd be caught by our own conscientious preparation.