Most people think the best business skill is creating novel and revolutionary ideas. I’d suggest to you that’s it’s leveraging information/content/resources and turning it into money, which will always come from certainty. Not just confidence, but certainty.
Selling your product or service will come down to whether or not you have 100% faith in the product and service you are selling. If not, your marketing efforts and sales efforts will be sabotaged due to your wavering belief.
Getting funding or presenting a proposal to investors will require you to be in a state of certainty as well.
Everything is about persuasion. The one who is most certain will influence the other person and dictate the terms.