The "prepared" part seems like good advice because many decisions can be made in advance, only contingent on future information. You might not be able to decide

The "prepared" part seems like good advice because many decisions can be made in advance, only contingent on future information. You might not be able to decide far in advance what exactly to do, but you might be able to decide what to do if X or Y happens, and what to do otherwise. Then when the moment comes and X happens, you can decide fast. The article talks a bit about imperfect information, which does throw a bit of a wrench in this, so it doesn't apply to every situation.