As a leader, your job will entail a never ending line of decisions that require your attention. From minute details to sweeping policy changes, you must be comfortable and confident in making decisions quickly.
But it's not just choosing A or B, you must have enough context and knowledge to know which is actually a better choice. How will your decision affect the team months or years down the road? Not only that, but there will surely be people who disagree, and you must be ready to defend your decision.
Further still, you must know the history surrounding a decision. Did you heir on the client or sales person side last time? Will you appear biased because you always tend to make a particular kind of decision?
Once you have a grasp on all the above, you must be prepared to make those decisions every. single. day.