The lifespan argument shows how important it is to have more than zero information.

Yes, it is valuable to have more than zero information.

But often we don't have the information that we wish. Even more often, the information that we have leads us to a story, that severely misleads us. Reminding ourselves of the zero information version of the story, can be an antidote to being mislead that way.

Therefore it is valuable to know how to make the most out of zero information. And if we have information, to think about exactly why it leads to a different conclusion.